Seal inspection jig and method for inspecting seal leakage

Abstract

The present invention provides a seal inspection jig that can be attached only when performing a leak test on the seal of a water-resistant external bearing device supporting the rotating shaft of a pump, and that allows the leak test to be performed at any desired timing. [Solution] The seal inspection jig 100 comprises a first structure 101 having an installation surface 103 to be attached to a water-resistant external bearing device 43, a second structure 102 that contacts the first structure 101, a first seal ring 105 positioned on the installation surface 103, and a second seal ring 106 sandwiched between the first structure 101 and the second structure 102. The first structure 101 has a fluid chamber 110. The second seal ring 106 is positioned between a first through hole 113 and a second through hole 115, and the second structure 102 is configured to be separable into multiple parts.

Description

Technical Field

[0001] The present invention relates to a seal inspection jig used for leak inspection of a seal of a water-resistant outer bearing device that supports the rotating shaft of a pump such as a vertical shaft pump or a horizontal shaft pump, and a method for leak inspection of a seal using the seal inspection jig.

Background Art

[0002] In a drainage airport that performs rainwater drainage, pumps such as vertical shaft pumps and horizontal shaft pumps are used. In a drainage airport where the installation level of this pump is lower than the ground level, there is a concern about flooding damage to the pump room during the approach of a large typhoon. When flooding of the drainage airport as described above is assumed, it is sufficient as a flood countermeasure to install a drive machine, a speed reducer, electrical equipment, etc. that drive the pump in a prime mover room that is higher than the ground level.

[0003] However, at present, the technology for flood countermeasures (waterproofing) for the pump itself has not been established. When the pump is flooded, the outer bearing device at the top of the pump is considered to be the most damaged. The outer bearing device is installed outside the pump casing and is arranged at a position where the water pumped up by the pump does not come into contact.

[0004] Inside the bearing chamber of the outer bearing device, a bearing that supports the rotating shaft of the pump is provided. When water enters the bearing chamber and the water comes into contact with the bearing, the corrosion of the bearing progresses, and eventually the operation of the vertical shaft pump becomes impossible. Therefore, the water-resistant outer bearing device has a seal for preventing the intrusion of water into the bearing chamber.

[0005] If the seal used for the water-resistant outer bearing device cannot sufficiently perform its function due to wear or the like, the seal cannot prevent the intrusion of water into the bearing chamber during a water level rise. Therefore, it is necessary to regularly inspect the seal. However, in order to remove the seal from the outer bearing device, it is necessary to disassemble the pump, which takes a great deal of cost and time. Therefore, as shown in Patent Documents 1-3 below, seal inspection technologies have been proposed. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 5-45246 [Patent Document 2] Japanese Patent Application Laid-Open No. 63-17168 [Patent Document 3] Japanese Patent Publication No. 2003-161669 [Overview of the project] [Problems that the invention aims to solve]

[0007] The above-mentioned Patent Document 1 discloses a leak detection device for a shaft seal. However, this leak detection device can only detect liquid leakage from the target shaft seal after it has occurred. Under normal circumstances, the shaft seal operates in an air environment without any liquid, so leak detection is not possible.

[0008] Patent document 2, mentioned above, discloses a technique for covering and sealing rotating machinery with a cover. However, this is not practical for large pumps such as vertical-shaft pumps and horizontal-shaft pumps, as it would require a large cover. Furthermore, removing the cover would incur significant costs and effort.

[0009] Patent Document 3 discloses an external water pressure testing device for pipe joints. However, applying this external water pressure testing device to a pump requires disassembling the pump, which is costly and time-consuming. It is conceivable to attach the external water pressure testing device described in Patent Document 3 to the pump during assembly, but since the rotating shaft rotates during pump operation, it is difficult to apply the external water pressure testing device to the pump.

[0010] Therefore, the present invention provides a seal inspection jig that can be attached only when performing a leak inspection of the seal of a water-resistant external bearing device supporting the rotating shaft of a pump, and that allows the leak inspection to be performed at any arbitrary timing. The present invention also relates to a method for performing a leak inspection of the seal of a water-resistant external bearing device using such a seal inspection jig. [Means for solving the problem]

[0011] In one embodiment, a seal inspection jig is provided for use in testing the leakage of a seal in a water-resistant external bearing device supporting the rotating shaft of a pump, comprising: a first structure having an mounting surface attached to the water-resistant external bearing device; a second structure in contact with the first structure; a first seal ring disposed on the mounting surface; and a second seal ring sandwiched between the first and second structures, wherein the first structure has a fluid chamber, an injection port for injecting a test fluid into the fluid chamber, and a first through hole communicating with the fluid chamber, the first through hole having a diameter larger than the rotating shaft; the second structure has a second through hole communicating with the first through hole, the second through hole having a diameter larger than the rotating shaft; the second seal ring is disposed between the first and second through holes; and the second structure is configured to be separable into a plurality of segments.

[0012] In one embodiment, the first structure is configured to be divisible into a plurality of segments. In one embodiment, the contact surface of the second structure that contacts the first structure has an annular tapered surface connected to the second through hole, and the second seal ring is sandwiched between the first structure and the tapered surface. In one embodiment, the contact surface of the first structure that contacts the second structure has an annular tapered surface connected to the first through hole, and the second seal ring is sandwiched between the second structure and the tapered surface. In one embodiment, the second seal ring has a configuration in which both end faces of a string-like seal element are joined together with an adhesive. In one embodiment, when a leak test of the seal is being performed, the second seal ring is pressed against the outer surface of the rotating shaft by the first structure and the second structure.

[0013] In one embodiment, a method for testing the leak of a seal in a water-resistant external bearing device supporting the rotating shaft of a pump is provided, the method comprising: attaching the seal testing jig to the water-resistant external bearing device; injecting a test fluid into the fluid chamber through the injection port; and then measuring the pressure of the test fluid in the fluid chamber for a predetermined test period. In one embodiment, the inspection fluid is a gas. In one embodiment, the inspection fluid is the same type of lubricant used in the water-resistant external bearing device.

[0014] In one embodiment, a method for testing the leak of a seal in a water-resistant external bearing device supporting the rotating shaft of a pump is provided, the method comprising: attaching the seal testing jig to the water-resistant external bearing device; injecting a test fluid into the fluid chamber through the injection port; and then measuring the pressure inside the bearing chamber of the water-resistant external bearing device for a predetermined test period.

[0015] In one embodiment, a method for testing the leak of a seal in a water-resistant external bearing device supporting the rotating shaft of a pump is provided, comprising attaching the seal testing jig to the water-resistant external bearing device and injecting a test fluid into the fluid chamber through the injection port, wherein the water-resistant external bearing device has a transparent window that allows visual confirmation of whether or not the test fluid is present in its bearing chamber. In one embodiment, the inspection fluid is a fluid in which fluorescent paint is mixed with the same type of lubricant used in the water-resistant external bearing device. In one embodiment, the water-resistant external bearing device has a hole in its bearing chamber through which an endoscope can be inserted.

[0016] In one aspect, there is provided a method for inspecting leakage of a seal of a water-resistant outer bearing device that supports a rotating shaft of a pump. The method includes attaching the seal inspection jig to a seal holder of the water-resistant outer bearing device, the seal being held by the seal holder, and injecting an inspection fluid into the fluid chamber through the injection port. The seal holder has an opening through which the rotating shaft passes and a through-hole communicating with the opening. In one aspect, the inspection fluid is a fluid in which a fluorescent paint is mixed with a lubricating oil of the same type as the lubricating oil used in the water-resistant outer bearing device.

Advantages of the Invention

[0017] Since the second structure is composed of a plurality of divided bodies, the second structure can be installed in the water-resistant outer bearing device without disassembling the pump. The first structure may be installed in the water-resistant outer bearing device during assembly of the pump, or alternatively, may be composed of a plurality of divided bodies in the same manner as the second structure. The seal inspection jig can be easily installed on the water-resistant outer bearing device at a desired timing. Therefore, the seal of the water-resistant outer bearing device can be inspected regularly.

Brief Description of the Drawings

[0018] [Figure 1] It is a schematic diagram showing an embodiment of a vertical shaft pump. [Figure 2] It is a cross-sectional view showing an embodiment of a water-resistant outer bearing device. [Figure 3] It is a cross-sectional view showing an embodiment of a seal inspection jig used for inspecting leakage of an upper seal and a lower seal of a water-resistant outer bearing device. [Figure 4] It is a perspective view of the first structure. [Figure 5] It is a plan view of the first structure shown in FIG. 4. [Figure 6] It is a view showing a state in which two divided bodies of the first structure are separated. [Figure 7] It is a side view of the divided body as viewed from the direction of line A-A shown in FIG. 6. [Figure 8]This is a perspective view of the second structure. [Figure 9] Figure 8 is a plan view of the second structure. [Figure 10] This figure shows the two divided parts of the second structure separated. [Figure 11] Figure 10 is a side view of the divided body as seen from the direction of line BB. [Figure 12] Figures 12(a) and 12(b) illustrate one embodiment of the process of attaching the first seal ring to the rotating shaft. [Figure 13] Figures 13(a) and 13(b) illustrate one embodiment of the process of attaching the second seal ring to the rotating shaft. [Figure 14] This figure illustrates one embodiment of the process of fixing the first structure and the second structure to a water-resistant external bearing device. [Figure 15] This is a cross-sectional view showing another embodiment of the seal inspection jig. [Figure 16] This diagram illustrates one embodiment of performing a leak test on the upper seal of a water-resistant external bearing device. [Figure 17] This diagram illustrates one embodiment of performing a leak test on the lower seal of a water-resistant external bearing device. [Figure 18] This figure illustrates another embodiment for performing a leak test on the upper seal of a water-resistant external bearing device. [Figure 19] This figure illustrates another embodiment for performing a leak test on the lower seal of a water-resistant external bearing device. [Figure 20] This figure illustrates yet another embodiment for performing a leak test on the upper seal of a water-resistant external bearing device. [Figure 21] This figure illustrates yet another embodiment for performing a leak test on the lower seal of a water-resistant external bearing device. [Figure 22] This figure illustrates yet another embodiment for performing a leak test on the upper seal of a water-resistant external bearing device. [Figure 23]This figure illustrates yet another embodiment for performing a leak test on the lower seal of a water-resistant external bearing device. [Figure 24] This figure illustrates yet another embodiment for performing a leak test on the upper seal of a water-resistant external bearing device. [Figure 25] This figure illustrates yet another embodiment for performing a leak test on the lower seal of a water-resistant external bearing device. [Figure 26] This figure illustrates yet another embodiment for performing a leak test on the upper seal of a water-resistant external bearing device. [Figure 27] This figure illustrates yet another embodiment for performing a leak test on the lower seal of a water-resistant external bearing device. [Figure 28] This figure shows one embodiment of a lower seal composed of a mechanical seal. [Figure 29] This figure shows another embodiment of the lower seal. [Figure 30] This figure shows yet another embodiment of the lower seal. [Figure 31] This figure shows yet another embodiment of the lower seal. [Figure 32] This figure shows another embodiment of a water-resistant external bearing device. [Figure 33] This is a cross-sectional view showing one embodiment of a horizontal-axis pump. [Modes for carrying out the invention]

[0019] Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a schematic diagram showing one embodiment of a vertical shaft pump. As shown in Figure 1, the vertical shaft pump 1 is a pump for pumping liquid from a suction tank 2. The vertical shaft pump 1 shown in Figure 1 is installed in a drainage pumping station for transferring tap water, rainwater, agricultural water, etc.

[0020] The vertical shaft pump 1 comprises a rotating shaft 15 extending vertically, an impeller 10 fixed to the rotating shaft 15, and a pump casing 27 that forms a passage for water pressurized by the impeller 10. The pump casing 27 comprises a discharge bowl 24 in which the impeller 10 is located, a suction bell mouth 22 connected to the lower end of the discharge bowl 24, a lifting pipe 28 connected to the upper end of the discharge bowl 24, a discharge bend 30 connected to the upper end of the lifting pipe 28, and a discharge pipe 34 connected to the discharge end of the discharge bend 30. The rotating shaft 15 is connected to a drive source 7 via a coupling 35. Examples of the drive source 7 include an electric motor, a diesel engine, and a gas turbine engine. The drive source 7 is installed on an installation floor 8 located above the pump installation floor 3.

[0021] The discharge bowl 24 and the suction bell mouth 22 are suspended in the suction tank 2 by a water lifting pipe 28. The suction bell mouth 22 has a downward-opening suction port 22a, and the upper end of the suction bell mouth 22 is connected to the lower end of the discharge bowl 24. The suction port 22a is formed at the lower end of the pump casing 27.

[0022] The water lifting pipe 28 extends downward through an opening 5 formed in the pump installation floor 3, which constitutes the upper wall of the suction tank 2. A mounting flange 33 is fixed to the upper end of the water lifting pipe 28. The mounting flange 33 is fixed to the pump installation floor 3 by foundation bolts (not shown). The rotating shaft 15 extends vertically through the discharge curved pipe 30 and the water lifting pipe 28, and the lower end of the rotating shaft 15 is located inside the discharge bowl 24.

[0023] The vertical shaft pump 1 is equipped with a submersible bearing 41 and a water-resistant external bearing device 43 for rotatably supporting the rotating shaft 15. The water-resistant external bearing device 43 is located outside the flow path of the pump casing 27 and, more specifically, is fixed to the upper part of the discharge curved pipe 30 which forms part of the pump casing 27.

[0024] The rotating shaft 15 protrudes upward from the discharge bend 30 and is connected to the drive source 7 via a coupling 35. A water-resistant external bearing device 43 rotatably supports the portion of the rotating shaft 15 that protrudes upward from the discharge bend 30. An underwater bearing 41 is located inside the discharge bowl 24 and supports the lower part of the rotating shaft 15. Additional underwater bearings supporting the rotating shaft 15 may be located inside the pumping pipe 28. Below the water-resistant external bearing device 43, an inspection port 45 is formed for inspecting a shaft seal device (not shown) that seals the gap between the rotating shaft 15 and the discharge bend 30.

[0025] An inner bowl 25 is located inside the discharge bowl 24, and the inner bowl 25 is connected to the discharge bowl 24 by a plurality of guide vanes 37. The underwater bearing 41 is located inside the inner bowl 25. The plurality of guide vanes 37 are located above (on the discharge side of) the impeller 10. A liquid flow path is formed between the inner surface of the discharge bowl 24 and the outer surface of the inner bowl 25.

[0026] The impeller 10 is located inside the suction tank 2. The drive source 7 rotates the rotating shaft 15 and the impeller 10 together. As the impeller 10 rotates, the liquid in the suction tank 2 is drawn in through the suction port 22a of the pump casing 27. The rotation of the impeller 10 causes the liquid to be transferred through the suction bell mouth 22, discharge bowl 24, lifting pipe 28, discharge bend 30, and discharge piping 34 that make up the pump casing 27.

[0027] Figure 2 is a cross-sectional view showing one embodiment of a water-resistant external bearing device 43. The water-resistant external bearing device 43 comprises bearings 47 and 48 that rotatably support a rotating shaft 15, a bearing housing 51 having a bearing chamber 50 inside which the bearings 47 and 48 are housed, an inner bearing cover 52 that covers the bearing chamber 50, and an outer bearing cover 53 that covers the inner bearing cover 52. Bearing 47 is located above bearing 48. The upper part of the rotating shaft 15 is connected to a coupling 35. More specifically, the coupling 35 has a lower coupling 35A connected to the rotating shaft 15 and an upper coupling 35B connected to the drive source 7 shown in Figure 1, and the upper part of the rotating shaft 15 is housed in a housing hole 55 formed in the lower coupling 35A. The upper coupling 35B and the lower coupling 35A are fixed to each other by bolts and nuts (not shown). A coupling cover that covers the entire coupling 35 may be provided.

[0028] The rotating shaft 15 has a threaded portion 57 formed on its outer circumference. A set ring nut 58 is screwed onto the threaded portion 57. The lower surface of the lower coupling 35A is in contact with the set ring nut 58. When the set ring nut 58 is rotated, it moves vertically on the threaded portion 57. This set ring nut 58 is provided for vertical positioning of the rotating shaft 15 and the entire coupling 35.

[0029] The rotating shaft 15 extends vertically through the entire water-resistant external bearing device 43. The rotating shaft 15 may consist of a single element, or it may consist of a rotating assembly including a main shaft and a shaft sleeve surrounding the main shaft. The shaft sleeve constitutes a portion of the outer circumferential surface of the rotating shaft 15.

[0030] The water-resistant external bearing device 43 further comprises an adjustment nut 60 located in the space Q between the outer bearing cover 53 and the inner bearing cover 52, and a journal 62 fixed to the outer surface of the rotating shaft 15. The journal 62 has a cylindrical shape, and the rotating shaft 15 extends through the journal 62. The journal 62 is rotatable integrally with the rotating shaft 15. The upper surface of the journal 62 is located in the space Q between the outer bearing cover 53 and the inner bearing cover 52, and the lower part of the journal 62 is located below the inner bearing cover 52 and within the bearing chamber 50.

[0031] The inner rings of bearing 47 and bearing 48 rotatably support the journal 62. Thus, the rotating shaft 15 and the journal 62 are rotatably supported by bearings 47 and bearing 48. The outer rings of bearing 47 and bearing 48 are held in the bearing housing 51. In this embodiment, bearing 47 is a radial rolling bearing configured to receive the radial load of the rotating shaft 15, and bearing 48 is an angular contact rolling bearing configured to receive the radial and axial loads of the rotating shaft 15. However, the configuration of bearings 47 and bearing 48 is not particularly limited, as long as they can receive the radial and axial loads of the rotating shaft 15.

[0032] The rotating shaft 15 extends through the adjustment nut 60. The adjustment nut 60 is screwed onto a threaded portion 64 formed on the outer circumferential surface of the rotating shaft 15. More specifically, the adjustment nut 60 has an internal threaded portion 65 that is screwed onto the threaded portion 64 of the rotating shaft 15. The adjustment nut 60 is in contact with the upper surface of the journal 62. When the adjustment nut 60 is rotated, the rotating shaft 15 moves up and down relative to the entire waterproof external bearing device 43. The adjustment nut 60 is provided for the vertical positioning of the rotating shaft 15 relative to the waterproof external bearing device 43.

[0033] The water-resistant external bearing device 43 has an oil cylinder 67 located inside the journal 62. The oil cylinder 67 is a cylindrical member extending upward from the lower part of the bearing housing 51, with its upper part located inside the journal 62. The oil cylinder 67 is provided to prevent lubricating oil for the bearings 47 and 48 from leaking from the bearing chamber 50. The oil cylinder 67 extends upward to a position higher than the bearing 47 and downward to a position lower than the bearing 48. The rotating shaft 15 extends through the oil cylinder 67. The lower end of the oil cylinder 67 is fixed to a seal holder 68. In one embodiment, the lower end of the oil cylinder 67 may be fixed to the bearing housing 51.

[0034] The journal 62 has an air vent passage 70 inside. The upper end of the air vent passage 70 opens in the space Q between the outer bearing cover 53 and the inner bearing cover 52, and the lower end of the air vent passage 70 opens in the internal space 71 of the journal 62 where the upper part of the oil cylinder 67 is located.

[0035] The water-resistant external bearing device 43 includes a vent pipe 73 extending upward from the outer bearing cover 53. This vent pipe 73 is removably connected to the outer bearing cover 53. The vent pipe 73 communicates with a bearing chamber 56 between the outer bearing cover 53 and the inner bearing cover 52, and the bearing chamber 56 communicates with a bearing chamber 50 through a through hole 74 formed in the inner bearing cover 52. The vent pipe 73 extends upward to a position higher than the coupling 35, and may extend upward to a position higher than, for example, the installation floor 8 on which the drive source 7 shown in Figure 1 is installed.

[0036] Within the bearing chamber 50, there are rotating and stationary parts, creating a pressure difference between them. This pressure difference generates a force that draws air in from outside the bearing chamber 50. Additionally, the heat generated by bearings 47 and 48 causes the air inside the bearing chamber 50 to expand. This force drawing in air and the expansion of the air cause air to circulate between the inside and outside of the bearing chamber 50 through the air vent passage 70 and the vent pipe 73. The air vent passage 70 communicates with the bearing chamber 56 between the outer bearing cover 53 and the inner bearing cover 52, and the vent pipe 73 communicates with this bearing chamber 56. Since the vent pipe 73 extends upward, even if the entire water-resistant outer bearing device 43 is submerged in water, water will not flow into the bearing chamber 56 and bearing chamber 50 through the vent pipe 73.

[0037] The water-resistant external bearing device 43 further includes an upper seal 81 for sealing the gap between the outer bearing cover 53, which is part of the bearing housing, and the rotating shaft 15, and a lower seal 82 for sealing the gap between the bearing housing 51 and the rotating shaft 15. The upper seal 81 and the lower seal 82 are sliding seals that slide against the outer circumferential surface of the rotating shaft 15. The water-resistant external bearing device 43 further includes an intermediate seal 83 for sealing the gap between the inner bearing cover 52 and the journal 62. This intermediate seal 83 is a sliding seal that slides against the outer circumferential surface of the journal 62.

[0038] The lower seal 82 is held in a seal holder 68 located on the bottom surface of the bearing housing 51. Between the bottom surface of the bearing housing 51 and the top surface of the seal holder 68 is a seal 69 (e.g., an O-ring) that surrounds the rotating shaft 15. The water-resistant external bearing device 43 further includes a stationary seal 86 (e.g., an O-ring) located between the outer bearing cover 53 and the inner bearing cover 52, and a stationary seal 87 (e.g., an O-ring) located between the inner bearing cover 52 and the bearing housing 51.

[0039] The upper seal 81, lower seal 82, stationary seal 86, and stationary seal 87 can prevent water from entering the bearing chambers 56 and 50 when the entire water-resistant external bearing unit 43 is submerged in water. More specifically, the upper seal 81 prevents water from entering the gap between the outer bearing cover 53 and the rotating shaft 15, the stationary seal 86 prevents water from entering the gap between the outer bearing cover 53 and the inner bearing cover 52, the stationary seal 87 prevents water from entering the gap between the inner bearing cover 52 and the bearing housing 51, and the lower seal 82 prevents water from entering the gap between the bearing housing 51 and the rotating shaft 15. If there is no inspection port 45 as shown in Figure 1, or if the inspection port 45 can be closed with a sealed cover, the lower seal 82 may not be provided.

[0040] The portion of the outer circumferential surface of the rotating shaft 15 that contacts the upper seal 81 is a smooth surface 90 formed by a surface smoothing process (e.g., surface polishing). The smooth surface 90 can improve contact with the upper seal 81 and more reliably prevent water intrusion. In addition, the smooth surface 90 can reduce wear on the upper seal 81, which is a sliding seal. Similarly, the portion of the outer circumferential surface of the rotating shaft 15 that contacts the lower seal 82 is also a smooth surface 91 formed by a surface smoothing process (e.g., surface polishing). The smooth surfaces 90 and 91 may also be formed on the outer circumferential surface of the shaft sleeve that constitutes part of the rotating shaft 15.

[0041] Figure 3 is a cross-sectional view showing one embodiment of a seal inspection jig used for leak testing of the upper seal 81 and lower seal 82 of a water-resistant external bearing device 43. The seal inspection jig 100 comprises a first structure 101 having an mounting surface 103 to be attached to the water-resistant external bearing device 43, a second structure 102 in contact with the first structure 101, a first seal ring 105 positioned on the mounting surface 103, and a second seal ring 106 sandwiched between the first structure 101 and the second structure 102.

[0042] The first structure 101 has a fluid chamber 110, an injection port 112 for injecting inspection fluid into the fluid chamber 110, and a first through hole 113 communicating with the fluid chamber 110. The injection port 112 extends from the fluid chamber 110 to the side of the first structure 101. The first through hole 113 has a circular cross-section and a diameter larger than the rotating shaft 15 of the vertical shaft pump. The second structure 102 has a second through hole 115 communicating with the first through hole 113. The second through hole 115 has a circular cross-section and a diameter larger than the rotating shaft 15 of the vertical shaft pump. When performing a leak test on the upper seal 81 and the lower seal 82, as shown in Figure 3, the mounting surface 103 of the first structure 101 is positioned facing the water-resistant external bearing device 43, and the rotating shaft 15 is positioned within the first through hole 113 and the second through hole 115.

[0043] The first structure 101 and the second structure 102 each have a plurality of first insertion holes 121 and a plurality of second insertion holes 122 into which a plurality of screws 118 are inserted. The plurality of first insertion holes 121 each communicate with the plurality of second insertion holes 122. When performing a leak test on the upper seal 81 and the lower seal 82, the plurality of screws 118 are inserted into the plurality of first insertion holes 121 and the plurality of second insertion holes 122 and screwed into a plurality of screw holes (not shown) formed in the water-resistant external bearing device 43. By tightening the screws 118, the first structure 101 and the second structure 102 are fixed to the water-resistant external bearing device 43.

[0044] The second seal ring 106 is positioned between the first through hole 113 and the second through hole 115. That is, the second seal ring 106 extends along the inner circumference of the first structure 101 and the second structure 102. The second seal ring 106 is in contact with both the first structure 101 and the second structure 102. The contact surface 127 of the second structure 102 that contacts the first structure 101 has an annular tapered surface 125 connected to the second through hole 115, and the second seal ring 106 is sandwiched between the contact surface 126 of the first structure 101 that contacts the second structure 102 and the tapered surface 125.

[0045] When the screw 118 is tightened, the first seal ring 105 is pressed against the water-resistant external bearing device 43 by the mounting surface 103 of the first structure 101, closing the gap between the mounting surface 103 of the first structure 101 and the water-resistant external bearing device 43. When the screw 118 is tightened, the second seal ring 106 is strongly squeezed between the first structure 101 and the second structure 102, deforming slightly radially inward and pressing against the outer circumferential surface of the rotating shaft 15. That is, the second seal ring 106 is pressed against the outer circumferential surface of the rotating shaft 15 by the first structure 101 and the second structure 102. As a result, the gap between the first structure 101 and the outer circumferential surface of the rotating shaft 15, and the gap between the second structure 102 and the outer circumferential surface of the rotating shaft 15 are closed by the second seal ring 106.

[0046] Figure 4 is a perspective view of the first structure 101. The mounting surface 103 of the first structure 101 has an endless seal groove 130 surrounding the fluid chamber 110. The first seal ring 105 is positioned within this endless seal groove 130. The inside of the first structure 101 is formed by a stepped portion 131, which forms the fluid chamber 110. In this embodiment, the first structure 101 is composed of a plurality of divided parts. In the embodiment shown in Figure 4, the first structure 101 can be divided into two divided parts 101A and 101B. In one embodiment, the first structure 101 may be composed of three or more divided parts.

[0047] Figure 5 is a plan view of the first structure 101 shown in Figure 4, and Figure 6 shows the state in which the two divided parts 101A and 101B of the first structure 101 have been separated. The two divided parts 101A and 101B each have mating surfaces 135 and 136. The mating surfaces 135 and 136 extend in the radial direction of the first structure 101. The mating surface 135 of divided part 101A faces the mating surface 136 of the other divided part 101B.

[0048] Figure 7 is a side view of the divided body 101A as seen from the direction of line AA shown in Figure 6. The first structure 101 is provided with a gasket 140 to seal the gap between the mating surfaces 135 and 136 of the two divided bodies 101A and 101B. In this embodiment, since there are two sets of mating surfaces 135 and 136, two gaskets 140 corresponding to the two sets of mating surfaces are provided. The gasket 140 is made of an elastic resin such as rubber or plastic. In one embodiment, the gasket 140 may be a liquid gasket. In other embodiments, instead of the gasket 140, a sealing member may be provided, which is placed in a groove formed in the mating surface 135 or mating surface 136. The sealing member extends from the installation surface 103 of the first structure 101 to the first through hole 113.

[0049] In one embodiment, the first structure 101 may be configured as a single structure without being divided. In this case, the first structure 101 is attached to the water-resistant external bearing device 43 together with the first seal ring 105 during the assembly of the vertical shaft pump. That is, the first structure 101 and the first seal ring 105 are always provided on the water-resistant external bearing device 43 during the operation of the vertical shaft pump and during leak testing.

[0050] Figure 8 is a perspective view of the second structure 102. The second structure 102 is composed of a plurality of divisions. In the embodiment shown in Figure 8, the second structure 102 can be divided into two divisions 102A and 102B. In one embodiment, the second structure 102 may be composed of three or more divisions.

[0051] Figure 9 is a plan view of the second structure 102 shown in Figure 8, and Figure 10 shows the second structure 102 separated into two parts 102A and 102B. The two parts 102A and 102B each have mating surfaces 151 and 152. The mating surfaces 151 and 152 extend in the radial direction of the second structure 102. The mating surface 151 of part 102A faces the mating surface 152 of the other part 102B.

[0052] Figure 11 is a side view of the divided body 102A as seen from the direction of line BB shown in Figure 10. The second structure 102 does not have a member equivalent to the sealing member 140 used in the first structure 101. The inner portion of the contact surface 127 of the second structure 102 that contacts the first structure 101 is inclined to form a tapered surface 125. The tapered surface 125 is connected to the inner circumferential surface 128 of the second structure 102 that forms the second through hole 115. The tapered surface 125 has a shape that extends radially outward from the second through hole 115.

[0053] Next, an embodiment of the process of attaching the seal inspection jig 100 of the embodiment described with reference to Figures 3 to 11 to the water-resistant external bearing device 43 will be described. First, as shown in Figure 12(a), a string-like first seal element 105a constituting the first seal ring 105 is prepared and placed near the rotating shaft 15 at a position below the water-resistant external bearing device 43. Then, as shown in Figure 12(b), the string-like first seal element 105a is curved along the outer circumferential surface of the rotating shaft 15, and both end faces of the first seal element 105a are joined with adhesive (not shown). This constitutes the endless shape of the first seal ring 105. The inner diameter of the first seal ring 105 is larger than the diameter of the rotating shaft 15.

[0054] Next, as shown in Figure 13(a), a string-shaped second seal element 106a constituting the second seal ring 106 is prepared and placed near the rotating shaft 15 at a position below the water-resistant external bearing device 43. Then, as shown in Figure 13(b), the string-shaped second seal element 106a is curved along the outer circumferential surface of the rotating shaft 15, and both end faces of the second seal element 106a are joined with adhesive (not shown). This constitutes an endless second seal ring 106. The inner diameter of the second seal ring 106 is the same as the diameter of the rotating shaft 15, and the second seal ring 106 contacts the outer circumferential surface of the rotating shaft 15.

[0055] Next, as shown in Figure 14, with the first seal ring 105 positioned in the endless seal groove 130 of the first structure 101 and the second seal ring 106 positioned between the tapered surfaces 125 of the first structure 101 and the second structure 102, the first structure 101 and the second structure 102 are fixed to the water-resistant external bearing device 43 by inserting a plurality of screws 118 into the first insertion hole 121 and the second insertion hole 122 and screwing the screws 118 into the screw holes (not shown) of the water-resistant external bearing device 43. Since the first structure 101 and the second structure 102 are each composed of divided parts 101A, 101B, 102A, and 102B, they can be attached to the water-resistant external bearing device 43 without disassembling the vertical shaft pump.

[0056] In one embodiment, the first structure 101 may have a tapered surface 125 instead of the second structure 102. For example, as shown in Figure 15, the contact surface 126 of the first structure 101 that contacts the second structure 102 may have an annular tapered surface 125 connected to the first through hole 113. The inner portion of the contact surface 126 of the first structure 101 that contacts the second structure 102 is inclined to form the tapered surface 125. The tapered surface 125 is connected to the inner circumferential surface of the first structure 101 that forms the first through hole 113. The second seal ring 106 is sandwiched between the second structure 102 and the tapered surface 125. In this configuration, when the screw 118 is tightened, the second seal ring 106 is strongly sandwiched between the first structure 101 and the second structure 102, deforming slightly radially inward and pressed against the outer circumferential surface of the rotating shaft 15.

[0057] Next, an embodiment of performing a leak test on the upper seal 81 of the water-resistant outer bearing device 43 using the seal inspection jig 100 described above will be explained. As shown in Figure 16, the seal inspection jig 100 is fixed to the upper surface of the outer bearing cover 53 of the water-resistant outer bearing device 43 so as to cover the upper seal 81. The upper seal 81 faces the fluid chamber 110. The installation of the seal inspection jig 100 is carried out according to the embodiment described with reference to Figures 12 to 14.

[0058] As shown in Figure 16, the inspection fluid supply line 161 is connected to the injection port 112. The inspection fluid supply line 161 is connected to the inspection fluid supply source 162, and the inspection fluid flows from the inspection fluid supply source 162 through the inspection fluid supply line 161 to the injection port 112, and then through the injection port 112 into the fluid chamber 110. In this embodiment, a gas such as air is used as the inspection fluid.

[0059] A first valve 165 is attached to the inspection fluid supply line 161. When this first valve 165 is closed, the injection of inspection fluid into the fluid chamber 110 is stopped. A pressure measuring line 166 is connected to the inspection fluid supply line 161. The connection point between the pressure measuring line 166 and the inspection fluid supply line 161 is located between the first valve 165 and the injection port 112. The pressure measuring line 166 is connected to a pressure gauge 167. A second valve 168 is attached to the pressure measuring line 166. When the second valve 168 is opened, the pressure gauge 167 communicates with the fluid chamber 110.

[0060] With the second valve 168 open, opening the first valve 165 allows the test fluid to be injected into the fluid chamber 110 through the test fluid supply line 161 and the injection port 112. The pressure of the test fluid in the fluid chamber 110 is measured by the pressure gauge 167. When the pressure of the test fluid in the fluid chamber 110 reaches the target value, the first valve 165 is closed, thereby closing the injection port 112. The second valve 168 remains open.

[0061] After closing the injection port 112 with the first valve 165, the pressure in the fluid chamber 110 is measured by the pressure measuring instrument 167 for a predetermined inspection time. If the pressure in the fluid chamber 110 remains above a threshold during the inspection time, the upper seal 81 is in good condition. If the pressure in the fluid chamber 110 drops below the threshold during the inspection time, it can be determined that the upper seal 81 is defective (e.g., worn). The seal inspection fixture 100 can be easily installed on the water-resistant external bearing device 43 at the desired timing. Therefore, the seal 81 of the water-resistant external bearing device 43 can be inspected periodically.

[0062] Using the seal inspection jig 100 described above, leakage testing of the lower seal 82 of the water-resistant external bearing device 43 can also be performed in the same manner. Specifically, as shown in Figure 17, the seal inspection jig 100 is fixed to the lower surface of the seal holder 68 of the water-resistant external bearing device 43 so as to cover the lower seal 82. In one embodiment, the seal inspection jig 100 may be fixed to the lower surface of the bearing housing 51 so as to cover the lower seal 82. The lower seal 82 faces the fluid chamber 110.

[0063] With the second valve 168 open, opening the first valve 165 allows the test fluid to be injected into the fluid chamber 110 through the test fluid supply line 161 and the injection port 112. The pressure of the test fluid in the fluid chamber 110 is measured by the pressure gauge 167. When the pressure of the test fluid in the fluid chamber 110 reaches the target value, the first valve 165 is closed, thereby closing the injection port 112. The second valve 168 remains open.

[0064] After closing the injection port 112 with the first valve 165, the pressure in the fluid chamber 110 is measured by the pressure measuring instrument 167 for a predetermined inspection time. If the pressure in the fluid chamber 110 remains above a threshold during the inspection time, the lower seal 82 is in good condition. If the pressure in the fluid chamber 110 drops below the threshold during the inspection time, it can be determined that there is a problem (e.g., wear) in the lower seal 82.

[0065] Figure 18 shows another embodiment in which a leak test of the upper seal 81 of the water-resistant outer bearing device 43 is performed using the seal inspection jig 100. The configuration and operation of this embodiment, which are not specifically described, are the same as those of the embodiment described with reference to Figure 16, so the redundant explanation is omitted. In this embodiment, as shown in Figure 18, the pressure measuring line 166 is in communication with the bearing chamber 56, and the pressure measuring instrument 167 measures the pressure inside the bearing chamber 56. In one example, the pressure measuring line 166 may be in communication with the bearing chamber 56 through the vent pipe 73 shown in Figure 1.

[0066] When the first valve 165 is opened, the inspection fluid is injected into the fluid chamber 110 through the inspection fluid supply line 161 and the injection port 112. Then, the first valve 165 is closed. After the injection port 112 is closed by the first valve 165, the pressure in the bearing chamber 56 is measured by the pressure measuring instrument 167 for a predetermined inspection time. If the pressure in the bearing chamber 56 remains below a threshold during the inspection time, the upper seal 81 is in good condition. If the pressure in the bearing chamber 56 rises above the threshold during the inspection time, it can be determined that there is a defect (e.g., wear) in the upper seal 81.

[0067] Figure 19 shows another embodiment in which a leak test of the lower seal 82 of the water-resistant external bearing device 43 is performed using the seal inspection jig 100. The configuration and operation of this embodiment, which are not specifically described, are the same as those of the embodiment described with reference to Figure 17, so the redundant explanation is omitted. In this embodiment, as shown in Figure 19, the pressure measuring line 166 is in communication with the bearing chamber 50, and the pressure measuring instrument 167 measures the pressure inside the bearing chamber 50. In one example, the pressure measuring line 166 may be in communication with the bearing chamber 50 through the vent pipe 73 and the bearing chamber 56 shown in Figure 1.

[0068] When the first valve 165 is opened, the inspection fluid is injected into the fluid chamber 110 through the inspection fluid supply line 161 and the injection port 112. Then, the first valve 165 is closed. After the injection port 112 is closed by the first valve 165, the pressure in the bearing chamber 50 is measured by the pressure measuring instrument 167 for a predetermined inspection time. If the pressure in the bearing chamber 50 remains below a threshold during the inspection time, the lower seal 82 is in good condition. If the pressure in the bearing chamber 50 rises above the threshold during the inspection time, it can be determined that there is a defect (e.g., wear) in the lower seal 82.

[0069] Figure 20 shows yet another embodiment in which a leak test of the upper seal 81 of the water-resistant external bearing device 43 is performed using the seal inspection jig 100. The configuration and operation of this embodiment, which are not specifically described, are the same as those of the embodiment described with reference to Figure 16, so a redundant explanation is omitted. In this embodiment, the same type of lubricant used for the water-resistant external bearing device 43 is used as the inspection fluid. The inspection fluid supply source 162 stores the lubricant inside.

[0070] As shown in Figure 20, the first structure 101 has an air vent hole 170 that communicates with the fluid chamber 110. The air vent hole 170 extends upward from the fluid chamber 110 and opens on the side of the first structure 101. When performing a leak test of the upper seal 81, a ventilation line 171 is connected to the air vent hole 170. The third valve 173 is attached to the ventilation line 171.

[0071] With the second valve 168 and the third valve 173 open, opening the first valve 165 allows the lubricating oil, as the inspection fluid, to be injected into the fluid chamber 110 through the inspection fluid supply line 161 and the injection port 112. The air in the fluid chamber 110 is then discharged through the ventilation line 171. After all the air has been discharged from the fluid chamber 110, the third valve 173 is closed. Whether all the air has been discharged from the fluid chamber 110 can be determined based on the lubricating oil that has leaked out of the ventilation line 171.

[0072] The pressure of the lubricating oil in the fluid chamber 110 is measured by a pressure gauge 167. When the pressure of the lubricating oil in the fluid chamber 110 reaches the target value, the first valve 165 is closed, thereby closing the injection port 112. The second valve 168 remains open.

[0073] After closing the injection port 112 with the first valve 165, the pressure in the fluid chamber 110 is measured by the pressure measuring instrument 167 for a predetermined inspection time. If the pressure in the fluid chamber 110 remains above a threshold during the inspection time, the upper seal 81 is in good condition. If the pressure in the fluid chamber 110 drops below the threshold during the inspection time, it can be determined that there is a defect (e.g., wear) in the upper seal 81.

[0074] In this embodiment, even if lubricating oil leaks from the fluid chamber 110 into the bearing chamber 56 due to a malfunction of the upper seal 81, the lubricating oil is already present in the bearing chamber 50, so the lubricating oil leaked from the fluid chamber 110 does not affect the bearing 48 in the bearing chamber 50 in any way.

[0075] Figure 21 shows yet another embodiment in which a leak test of the lower seal 82 of the water-resistant external bearing device 43 is performed using the seal inspection jig 100. The configuration and operation of this embodiment, which are not specifically described, are the same as those of the embodiment described with reference to Figure 17, so a redundant explanation is omitted. In this embodiment, the same type of lubricant used for the water-resistant external bearing device 43 is used as the inspection fluid. The inspection fluid supply source 162 stores the lubricant inside.

[0076] As shown in Figure 21, the seal holder 68 that holds the lower seal 82 has an air vent hole 175 that communicates with the fluid chamber 110. The air vent hole 175 extends upward from the fluid chamber 110 and opens on the side of the seal holder 68. When performing a leak test of the lower seal 82, a ventilation line 171 is connected to the air vent hole 175. The third valve 173 is attached to the ventilation line 171.

[0077] With the second valve 168 and the third valve 173 open, opening the first valve 165 allows the lubricating oil, as the inspection fluid, to be injected into the fluid chamber 110 through the inspection fluid supply line 161 and the injection port 112. The air in the fluid chamber 110 is then discharged through the ventilation line 171. After all the air has been discharged from the fluid chamber 110, the third valve 173 is closed. Whether all the air has been discharged from the fluid chamber 110 can be determined based on the lubricating oil that has leaked out of the ventilation line 171.

[0078] The pressure of the lubricating oil in the fluid chamber 110 is measured by a pressure gauge 167. When the pressure of the lubricating oil in the fluid chamber 110 reaches the target value, the first valve 165 is closed, thereby closing the injection port 112. The second valve 168 remains open.

[0079] After closing the injection port 112 with the first valve 165, the pressure in the fluid chamber 110 is measured by the pressure measuring instrument 167 for a predetermined inspection time. If the pressure in the fluid chamber 110 remains above a threshold during the inspection time, the lower seal 82 is in good condition. If the pressure in the fluid chamber 110 drops below the threshold during the inspection time, it can be determined that there is a problem (e.g., wear) in the lower seal 82.

[0080] In this embodiment, even if lubricating oil leaks from the fluid chamber 110 into the bearing chamber 50 due to a malfunction of the lower seal 82, the lubricating oil is already present in the bearing chamber 50, so the lubricating oil leaked from the fluid chamber 110 does not affect the bearing 48 in the bearing chamber 50 in any way.

[0081] Figure 22 shows yet another embodiment in which a leak test of the upper seal 81 of the water-resistant external bearing device 43 is performed using the seal inspection jig 100. The configuration and operation of this embodiment, which are not specifically described, are the same as those of the embodiment described with reference to Figure 20, so the redundant explanation is omitted. The inspection fluid used in this embodiment is a fluid in which fluorescent paint is mixed with the same type of lubricant used in the water-resistant external bearing device 43. The outer bearing cover 53, which is part of the bearing housing, is provided with a transparent window 180 facing the bearing chamber 56.

[0082] An inspection fluid consisting of lubricating oil mixed with fluorescent paint is injected into the fluid chamber 110 of the seal inspection jig 100 via the inspection fluid supply line 161. If there is a defect (e.g., wear) in the upper seal 81, the inspection fluid leaks from the fluid chamber 110 into the bearing chamber 56. When ultraviolet light emitted from a black light 181 is shone into the inside of the bearing chamber 56 through the transparent window 180, the fluorescent paint glows. By visually confirming that the fluorescent paint is glowing through the transparent window 180, the worker can determine that there is a defect (e.g., wear) in the upper seal 81.

[0083] Figure 23 shows yet another embodiment in which a leak test of the lower seal 82 of the water-resistant external bearing device 43 is performed using the seal inspection jig 100. The configuration and operation of this embodiment, which are not specifically described, are the same as those of the embodiment described with reference to Figure 21, so the redundant explanation is omitted. The inspection fluid used in this embodiment is a fluid in which fluorescent paint is mixed with the same type of lubricant used in the water-resistant external bearing device 43. The bearing housing 51 is provided with a transparent window 182 facing the bearing chamber 50.

[0084] An inspection fluid consisting of lubricating oil mixed with fluorescent paint is injected into the fluid chamber 110 of the seal inspection jig 100 via the inspection fluid supply line 161. If there is a defect (e.g., wear) in the lower seal 82, the inspection fluid leaks from the fluid chamber 110 into the bearing chamber 50. When ultraviolet light emitted from a black light 181 is shone into the inside of the bearing chamber 50 through the transparent window 182, the fluorescent paint glows. By visually confirming that the fluorescent paint is glowing through the transparent window 182, the worker can determine that there is a defect (e.g., wear) in the lower seal 82.

[0085] Figure 24 shows yet another embodiment in which a leak test of the upper seal 81 of the water-resistant outer bearing device 43 is performed using the seal inspection jig 100. The configuration and operation of this embodiment, which are not specifically described, are the same as those of the embodiment described with reference to Figure 20, so the redundant description is omitted. The inspection fluid used in this embodiment is the same type of lubricant used in the water-resistant outer bearing device 43. The outer bearing cover 53, which is part of the bearing housing, is provided with a through hole 185 that communicates with the bearing chamber 56. During normal operation of the vertical shaft pump, the through hole 185 is closed with a cover or plug (not shown).

[0086] The inspection fluid, consisting of lubricating oil, is injected into the fluid chamber 110 of the seal inspection fixture 100 through the inspection fluid supply line 161. If there is a defect (e.g., wear) in the upper seal 81, the inspection fluid leaks from the fluid chamber 110 into the bearing chamber 56. An endoscope 188 is inserted into the bearing chamber 56 through the through hole 185, and the tip of the endoscope 188 is brought to the vicinity of the upper seal 81. By visually confirming the presence of inspection fluid near the upper seal 81 using the endoscope 188, the worker can determine that there is a defect (e.g., wear) in the upper seal 81.

[0087] In one embodiment, in order to improve the visibility of the inspection fluid leaking into the bearing chamber 56 through the upper seal 81, the inspection fluid may be a fluid in which fluorescent paint is mixed with the same type of lubricant used in the water-resistant outer bearing device 43. In this case, an endoscope equipped with a black light is used.

[0088] Figure 25 shows yet another embodiment in which a leak test of the lower seal 82 of the water-resistant external bearing device 43 is performed using a seal inspection jig 100. The configuration and operation of this embodiment, which are not specifically described, are the same as those of the embodiments described with reference to Figures 21 and 24, so redundant descriptions are omitted. The inspection fluid used in this embodiment is the same type of lubricant used in the water-resistant external bearing device 43.

[0089] The inspection fluid, consisting of lubricating oil, is injected into the fluid chamber 110 of the seal inspection fixture 100 through the inspection fluid supply line 161. If there is a problem with the lower seal 82 (e.g., wear), the inspection fluid leaks from the fluid chamber 110 into the bearing chamber 50. More specifically, the inspection fluid leaks into the oil cylinder 67. Although lubricating oil for lubricating the bearing 48 is present inside the bearing chamber 50, the lower end of the oil cylinder 67 is fixed to the seal holder 68, and the oil cylinder 67 extends above the bearing chamber 50, so there is no lubricating oil inside the oil cylinder 67. Therefore, the inspection fluid that leaks through the lower seal 82 accumulates inside the oil cylinder 67.

[0090] The endoscope 188 is inserted into the bearing chamber 56 through the through hole 185, and further inserted into the air vent passage 70 and the oil cylinder 67, so that the tip of the endoscope 188 reaches the vicinity of the lower seal 82. By visually confirming the presence of lubricating oil near the lower seal 82 using the endoscope 188, the worker can determine that there is a problem (e.g., wear) with the lower seal 82.

[0091] In one embodiment, in order to improve the visibility of the inspection fluid leaking into the oil cylinder 67 through the lower seal 82, the inspection fluid may be a fluid in which fluorescent paint is mixed with the same type of lubricant used in the water-resistant external bearing device 43. In this case, an endoscope equipped with a black light is used.

[0092] Figure 26 shows yet another embodiment in which a leak test of the upper seal 81 of the water-resistant external bearing device 43 is performed using a seal inspection jig 100. The configuration and operation of this embodiment, which are not specifically described, are the same as those of the embodiment described with reference to Figure 20, so a redundant explanation is omitted.

[0093] The inspection fluid used in this embodiment is the same type of lubricant used in the water-resistant external bearing device 43. The upper seal 81 is held in a seal holder 190, which is fixed to the upper surface of the outer bearing cover 53, which is part of the bearing housing. The seal holder 190 has an opening 191 through which the rotating shaft 15 passes, and a through hole 192 communicating with the opening 191. The through hole 192 is open on the side of the seal holder 190. The through hole 192 and the opening 191 communicate with the bearing chamber 56. The through hole 192 is blocked by a plug (not shown) during normal operation of the vertical shaft pump 1. The plug is, for example, a screw-in plug.

[0094] The inspection fluid, consisting of lubricating oil, is injected into the fluid chamber 110 of the seal inspection fixture 100 through the inspection fluid supply line 161. If there is a defect (e.g., wear) in the upper seal 81, the inspection fluid leaks from the fluid chamber 110 into the bearing chamber 56. An operator can observe the opening 191 of the seal holder 190 through the through hole 192. By visually confirming the presence of the inspection fluid in the opening 191, the operator can determine that there is a defect (e.g., wear) in the upper seal 81.

[0095] In one embodiment, in order to improve the visibility of the inspection fluid leaking into the bearing chamber 56 through the upper seal 81, the inspection fluid may be a fluid in which fluorescent paint is mixed with the same type of lubricant used in the water-resistant outer bearing device 43. In this case, a black light 181 is used.

[0096] Figure 27 shows yet another embodiment in which a leak test of the lower seal 82 of the water-resistant external bearing device 43 is performed using a seal inspection jig 100. The configuration and operation of this embodiment, which are not specifically described, are the same as those of the embodiment described with reference to Figure 21, so a redundant explanation is omitted.

[0097] The inspection fluid used in this embodiment is the same type of lubricant used in the water-resistant external bearing device 43. The lower seal 82 is held in a seal holder 68, which is fixed to the lower surface of the bearing housing 51. The seal holder 68 has an opening 195 through which the rotating shaft 15 passes, and a through hole 196 communicating with the opening 195. The through hole 196 is open on the side of the seal holder 68. The through hole 196 and the opening 195 communicate with the bearing chamber 50. The through hole 196 is blocked by a plug (not shown) during normal operation of the vertical shaft pump. The plug is, for example, a screw-in plug.

[0098] The inspection fluid, consisting of lubricating oil, is injected into the fluid chamber 110 of the seal inspection fixture 100 through the inspection fluid supply line 161. If there is a defect (e.g., wear) in the lower seal 82, the inspection fluid leaks from the fluid chamber 110 into the bearing chamber 50. An operator can observe the opening 195 of the seal holder 68 through the through hole 196. By visually confirming the presence of the inspection fluid in the opening 195, the operator can determine that there is a defect (e.g., wear) in the lower seal 82.

[0099] In one embodiment, in order to improve the visibility of the inspection fluid leaking into the bearing chamber 50 through the lower seal 82, the inspection fluid may be a fluid in which fluorescent paint is mixed with the same type of lubricant used in the water-resistant outer bearing device 43. In this case, a black light 181 is used.

[0100] Each embodiment of the seal inspection jig 100 described so far can be applied to leak inspection of various types of seals, such as packings, mechanical seals, magnetic fluid seals, and fluid expansion seals. For example, in the embodiment shown in Figure 28, the lower seal 82 is made of a mechanical seal. More specifically, the lower seal 82 comprises a fixed-side member 201 fixed to the bearing housing 51, a rotating-side member 202 fixed to the rotating shaft 15, a seal element 203 supported by the fixed-side member 201, and a spring 204 that presses the seal element 203 against the rotating-side member 202. The seal element 203 has an annular shape arranged around the rotating shaft 15.

[0101] When performing a leak test on the lower seal 82, which consists of a mechanical seal, the seal inspection fixture 100 is attached to the bottom surface of the bearing housing 51, as shown in Figure 28. The entire lower seal 82, including the fixed side member 201, the rotating side member 202, the seal element 203, and the spring 204, is covered by the seal inspection fixture 100.

[0102] Although not shown in the diagram, the upper seal 81 shown in Figure 2 may also be a mechanical seal. In this case, when performing a leak test on the upper seal 81, the seal inspection jig 100 is attached to the upper surface of the outer bearing cover 53 (see Figure 2) so as to cover the entire upper seal 81 which is made of a mechanical seal.

[0103] Figure 29 shows yet another embodiment of the lower seal 82. In the embodiment shown in Figure 29, the lower seal 82 comprises a fixed-side member 201 fixed to the bearing housing 51, a rotating-side member 202 fixed to the rotating shaft 15, and a sealing element 203 supported by the fixed-side member 201 and pressed against the rotating-side member 202.

[0104] An O-ring 205 is positioned between the bottom surface of the bearing housing 51 and the fixed-side member 201. The O-ring 205 extends to surround the rotating shaft 15. The gap between the bearing housing 51 and the fixed-side member 201 is sealed by the O-ring 205. In the embodiment shown in Figure 29, the O-ring 205 is provided on the upper surface of the fixed-side member 201, but in one embodiment, the O-ring 205 may be provided on the bottom surface of the bearing housing 51.

[0105] The sealing element 203 has an annular shape and is positioned around the rotating shaft 15. The sealing element 203 is sandwiched between the stationary member 201 and the rotating member 202. The configuration of the sealing element 203 in Figure 29 is not particularly limited, but for example, the sealing element 203 may be a seal with a cross-sectional shape that opens outward to receive water pressure.

[0106] When performing a leak test on the lower seal 82 shown in Figure 29, the seal inspection fixture 100 is attached to the bottom surface of the bearing housing 51. The entire lower seal 82, including the fixed-side member 201, the rotating-side member 202, and the seal element 203, is covered by the seal inspection fixture 100.

[0107] Although not shown, the upper seal 81 shown in Figure 2 may have the same configuration as the lower seal 82 shown in Figure 29. In this case, when performing a leak test on the upper seal 81, the seal inspection jig 100 is attached to the upper surface of the outer bearing cover 53 (see Figure 2) so as to cover the entire upper seal 81.

[0108] Figure 30 shows yet another embodiment of the lower seal 82. The lower seal 82 is a magnetic fluid seal having an electromagnet 210 that forms a magnetic field and a magnetic fluid 211 placed in the magnetic field. The electromagnet 210 is connected to a power supply device (not shown). The magnetic fluid 211 has an annular shape that extends around the rotating shaft 15. An O-ring 212 is placed between the lower seal 82 and the bottom surface of the bearing housing 51. The O-ring 212 extends to surround the rotating shaft 15. The gap between the bottom surface of the bearing housing 51 and the lower seal 82 is sealed by the O-ring 212. In the embodiment shown in Figure 30, the O-ring 212 is located on the bottom surface of the bearing housing 51. In one embodiment, the O-ring 212 may be located on the upper surface of the lower seal 82.

[0109] During normal operation of the vertical shaft pump 1 shown in Figure 1, no power is supplied to the electromagnet 210, and the magnetic fluid 211 is not in contact with the rotating shaft 15. When a rise in flood level is expected due to typhoons, heavy rains, etc., power is supplied to the electromagnet 210 from the power supply device. As a result, the magnetic fluid 211 comes into contact with the outer surface of the rotating shaft 15, sealing the space between the bearing housing 51 and the rotating shaft 15.

[0110] When performing a leak test on the lower seal 82, which consists of a magnetic fluid seal, the seal inspection fixture 100 is attached to the bottom surface of the bearing housing 51, as shown in Figure 30. The entire lower seal 82, including the electromagnet 210 and magnetic fluid 211, is covered by the seal inspection fixture 100.

[0111] Although not shown in the figure, the upper seal 81 shown in Figure 2 may also be made of a magnetic fluid seal. In this case, when performing a leak test on the upper seal 81, the seal inspection jig 100 is attached to the upper surface of the outer bearing cover 53 (see Figure 2) so as to cover the entire upper seal 81 which is made of a magnetic fluid seal.

[0112] Figure 31 shows yet another embodiment of the lower seal 82. The lower seal 82 is a gas-expanding seal comprising a balloon ring 220 that contacts and is able to move away from the rotating shaft 15, and a balloon housing 221 that houses the balloon ring 220. The balloon ring 220 is connected to a gas supply device (not shown). The balloon ring 220 has an annular shape that extends around the rotating shaft 15.

[0113] An O-ring 222 is positioned between the balloon housing 221 and the bottom surface of the bearing housing 51. The O-ring 222 extends to surround the rotating shaft 15. The gap between the bottom surface of the bearing housing 51 and the balloon housing 221 is sealed by the O-ring 222. In the embodiment shown in Figure 31, the O-ring 222 is positioned on the bottom surface of the bearing housing 51, but in one embodiment, the O-ring 222 may be positioned on the top surface of the balloon housing 221.

[0114] During normal operation of the vertical shaft pump 1 shown in Figure 1, no gas is supplied to the balloon ring 220, and the balloon ring 220 is not in contact with the rotating shaft 15. When a rise in flood level is expected due to typhoons, heavy rains, etc., gas is supplied to the balloon ring 220 from a gas supply device (not shown), as shown in Figure 31, and the balloon ring 220 expands. As a result, the balloon ring 220 comes into contact with the outer surface of the rotating shaft 15, sealing the space between the bearing housing 51 and the rotating shaft 15.

[0115] When performing a leak test on the lower seal 82, which consists of a gas-expanded seal, the seal inspection fixture 100 is attached to the bottom surface of the bearing housing 51, as shown in Figure 31. The entire lower seal 82, including the balloon ring 220 and balloon housing 221, is covered by the seal inspection fixture 100.

[0116] Although not shown in the diagram, the upper seal 81 shown in Figure 2 may also be made of a gas-expanding seal. In this case, when performing a leak test on the upper seal 81, the seal inspection jig 100 is attached to the upper surface of the outer bearing cover 53 (see Figure 2) so as to cover the entire upper seal 81 which is made of a gas-expanding seal.

[0117] Figure 32 is a cross-sectional view showing yet another embodiment of the water-resistant external bearing device 43. The configuration and operation of this embodiment, which are not specifically described, are the same as those of the embodiment described with reference to Figure 2, so redundant descriptions are omitted. In this embodiment, the upper seal 81 is not provided. Also, the outer bearing cover 53 is not provided. In the embodiments described below, the inner bearing cover 52 is simply referred to as the bearing cover 52.

[0118] The water-resistant external bearing device 43 includes a nut cover 230 that houses the adjustment nut 60, a seal 231 for sealing the gap between the bearing cover 52 and the outer circumferential surface of the journal 62, a seal 232 for sealing the gap between the nut cover 230 and the outer circumferential surface of the rotating shaft 15, and a seal 233 for sealing the gap between the nut cover 230 and the journal 62.

[0119] The adjustment nut 60 is screwed onto a threaded portion 64 formed on the outer circumferential surface of the rotating shaft 15. More specifically, the inner threaded portion 65 of the adjustment nut 60 is screwed onto the threaded portion 64 of the rotating shaft 15. The upper surface of the journal 62 is located above the bearing cover 52, and the lower surface of the journal 62 is located below the bearing cover 52 and within the bearing chamber 50. The journal 62 is rotatably supported within the bearing chamber 50 by bearings 47 and 48.

[0120] The configuration of the seal 231 is not particularly limited, but for example, the seal 231 may be a sliding seal having a cross-sectional shape that opens outward to receive water pressure. The seal 231 can prevent water from flowing in through the gap between the bearing cover 52 and the outer surface of the journal 62 when the flood level rises due to typhoons or heavy rains.

[0121] Seals 232 and 233 are held in place by the nut cover 230. The nut cover 230, the adjustment nut 60, seals 232 and 233 rotate together with the rotating shaft 15. Examples of seals 232 and 233 include O-rings. The nut cover 230 is positioned above the upper surface of the journal 62 and encloses the entire adjustment nut 60. Seal 232 is positioned between the inner surface of the nut cover 230 and the outer surface of the rotating shaft 15, sealing the gap between the inner surface of the nut cover 230 and the outer surface of the rotating shaft 15. Seal 233 is positioned between the lower surface of the nut cover 230 and the upper surface of the journal 62, sealing the gap between the lower surface of the nut cover 230 and the upper surface of the journal 62. The nut cover 230 itself has a structure that does not allow fluid flow (i.e., a non-perforated structure). Therefore, a sealed space is formed inside the nut cover 230, and the adjustment nut 60 is positioned within this sealed space.

[0122] Even if the flood level rises due to typhoons or heavy rains, the water will not reach the sealed space inside the nut cover 230. Therefore, the water will not come into contact with the adjustment nut 60, and furthermore, the water will not enter through the gap between the adjustment nut 60 and the rotating shaft 15, nor through the gap between the journal 62 and the rotating shaft 15.

[0123] When performing a leak test on the sliding seal 231, the seal inspection jig 100 is attached to the upper surface of the bearing cover 52, as shown in Figure 32. The seal 231 is covered by the seal inspection jig 100.

[0124] In the embodiment described above, the seal inspection jig 100 is applied to a water-resistant external bearing device 43 of a vertical shaft pump. However, the seal inspection jig 100 can be applied not only to vertical shaft pumps but also to other types of pumps having a water-resistant external bearing device. For example, the seal inspection jig 100 can also be applied to a horizontal shaft pump shown in Figure 33. This horizontal shaft pump comprises a rotating shaft 301 extending horizontally, an impeller 302 fixed to the rotating shaft 301, and a pump casing 305 that forms a water flow path inside. The pump casing 305 comprises a discharge bowl 307 in which the impeller 302 is located, and a suction bend 308 connected to the discharge bowl 307. The rotating shaft 301 is connected to a drive source (not shown).

[0125] The horizontal-axis pump further comprises a water-resistant external bearing device 311 for rotatably supporting the rotating shaft 301. This water-resistant external bearing device 311 is located outside the flow path of the pump casing 305, and more specifically, is fixed to the side of the suction bend 308 which forms part of the pump casing 305. The basic configuration of the water-resistant external bearing device 311 is the same as that of the embodiment described with reference to Figure 2. That is, the water-resistant external bearing device 311 comprises a bearing 313 for rotatably supporting the rotating shaft 301, a bearing housing 315 in which the bearing 313 is housed, and two seals 317, 318 for sealing the gap between the bearing housing 315 and the rotating shaft 301.

[0126] The above-described embodiment of the seal inspection jig 100 and the leak inspection method using the seal inspection jig 100 can be applied to leak inspection of these seals 317 and 318.

[0127] The embodiments described above are intended to enable persons with ordinary skill in the art to implement the present invention. Various modifications of the above embodiments can be made naturally by those skilled in the art, and the technical idea of ​​the present invention can be applied to other embodiments as well. Therefore, the present invention is not limited to the embodiments described, but is to be interpreted in the broadest sense according to the technical idea defined by the claims. [Explanation of symbols]

[0128] 1. Vertical shaft pump 2. Suction tank 3 Pump installation floor 5 aperture 7. Power source 8 Installation floor 10 Impeller 15 Rotation axis 22 Intake Bell Mouth 22a Inlet 24 Discharge bowls 25 Inner bowl 27 Pump Casing 28 Water pumping pipe 30 Discharge bent pipe 33 Mounting flange 34 Discharge piping 35 Coupling 35A Lower coupling 35B Upper coupling 35C Intermediate coupling 37 Guide vanes 41 Underwater bearings 43 Water-resistant outer bearing device 45 Inspection hatch 47,48 Bearings 50 Bearing chamber 51 Bearing housing 52 Inner bearing cover 53 Outer bearing cover 55 housing holes 56 Bearing chamber 57 Threaded section 58 Set ring nuts 60 Adjustment Nut 62 Journals 64 Threaded part 65 Internal threaded section 67 Oil cylinder 68 Seal holder 69 Seals 70 Air vent passage 71 Interior space 73. Vent 74 Through hole 81, 82, 83 Seals 86,87 Static seal 90,91 smooth surface 100 seal inspection fixtures 101 First structure 101A,101B Split body 102 Second structure 102A, 102B split body 103 Installation surface 105 First seal ring 105a First sealing element 106 Second seal ring 106a Second seal element 110 Fluid chamber 112 injection port 113 1st hole 115 2nd hole 118 screws 121 First insertion hole 122 Second insertion hole 125 Tapered surface 126 Contact surface 127 Contact surface 128 Inner surface 130 seal groove 131 Multilayered section 135,136 mating surfaces 140 Gasket 151,152 mating surfaces 161 Inspection fluid supply line 162 Inspection fluid supply source 165 First valve 166 Pressure Measurement Line 167 Pressure measuring instrument 168 Second valve 170 air vents 171 Ventilation lines 173 Third valve 175 air vent holes 180 Transparent window 181 Blacklight 182 Transparent window 185 Through hole 188 Endoscope 190 Seal Holder 191 Aperture 192 Through hole 195 Aperture 196 Through hole 201 Fixed side member 202 Rotating side member 203 Seal elements 204 spring 205 O-ring 210 Electromagnet 211 Magnetic fluid 212 O-rings 220 Balloon Rings 221 Balloon Housing 222 O-ring 230 Nut Cover 231 Seals 232 Seals 233 Seals 301 Rotation axis 302 Impeller 305 Pump Casing 307 Discharge bowl 308 Suction bend 311 Waterproof external bearing device 313 Tactics 315 Bearing Housing 317,318 stickers

Claims

1. A seal inspection jig used for leak testing of seals in a water-resistant external bearing device that supports the rotating shaft of a pump, A first structure having an mounting surface to which the water-resistant external bearing device is attached, A second structure in contact with the first structure, A first seal ring positioned on the aforementioned mounting surface, A second seal ring is sandwiched between the first structure and the second structure, The first structure has a fluid chamber, an injection port for injecting inspection fluid into the fluid chamber, and a first through hole communicating with the fluid chamber, the first through hole having a diameter larger than the rotation axis, The second structure has a second through-hole that communicates with the first through-hole, and the second through-hole has a diameter larger than the rotation axis. The second seal ring is positioned between the first through hole and the second through hole. The second structure is a seal inspection jig configured to be separable into multiple segments.

2. The seal inspection jig according to claim 1, wherein the first structure is configured to be divisible into a plurality of segments.

3. The seal inspection jig according to claim 1, wherein the contact surface of the second structure that contacts the first structure has an annular tapered surface connected to the second through hole, and the second seal ring is sandwiched between the first structure and the tapered surface.

4. The seal inspection jig according to claim 1, wherein the contact surface of the first structure that contacts the second structure has an annular tapered surface connected to the first through hole, and the second seal ring is sandwiched between the second structure and the tapered surface.

5. The seal inspection jig according to claim 1, wherein the second seal ring has a configuration in which both end faces of a string-shaped seal element are joined with an adhesive.

6. The seal inspection jig according to claim 1, wherein the second seal ring is pressed against the outer surface of the rotating shaft by the first structure and the second structure when the seal leak test is being performed.

7. A method for testing the leakage of a seal in a water-resistant external bearing device that supports the rotating shaft of a pump, The seal inspection jig according to any one of claims 1 to 6 is attached to the water-resistant external bearing device, The test fluid is injected into the fluid chamber through the injection port, and then, A leak test method comprising measuring the pressure of the test fluid in the fluid chamber for a predetermined test period.

8. The leak inspection method according to claim 7, wherein the inspection fluid is a gas.

9. The leak inspection method according to claim 7, wherein the inspection fluid is the same type of lubricant used in the water-resistant external bearing device.

10. A method for testing the leakage of a seal in a water-resistant external bearing device that supports the rotating shaft of a pump, The seal inspection jig according to any one of claims 1 to 6 is attached to the water-resistant external bearing device, The test fluid is injected into the fluid chamber through the injection port, and then, A leak test method comprising measuring the pressure inside the bearing chamber of the aforementioned water-resistant external bearing device for a predetermined test period.

11. A method for testing the leakage of a seal in a water-resistant external bearing device that supports the rotating shaft of a pump, The seal inspection jig according to any one of claims 1 to 6 is attached to the water-resistant external bearing device, This includes injecting the inspection fluid into the fluid chamber through the injection port, A leak inspection method comprising a water-resistant external bearing device having a transparent window that allows visual confirmation of whether or not the inspection fluid is present in the bearing chamber.

12. The leak inspection method according to claim 11, wherein the inspection fluid is a fluid in which fluorescent paint is mixed with the same type of lubricant used in the water-resistant external bearing device.

13. The leak inspection method according to claim 11, wherein the water-resistant external bearing device has a hole in its bearing chamber into which an endoscope can be inserted.

14. A method for testing the leakage of a seal in a water-resistant external bearing device that supports the rotating shaft of a pump, The seal inspection jig according to any one of claims 1 to 4 is attached to the seal holder of the water-resistant external bearing device, and the seal is held in the seal holder. This includes injecting the inspection fluid into the fluid chamber through the injection port, A leak inspection method comprising a seal holder having an opening through which the rotating shaft passes and a through hole communicating with the opening.

15. The leak inspection method according to claim 14, wherein the inspection fluid is a fluid in which fluorescent paint is mixed with the same type of lubricant used in the water-resistant external bearing device.

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