Vertical shaft pump

Abstract

To simplify a protection mechanism for a submerged bearing used in a vertical shaft pump.SOLUTION: A vertical shaft pump 10 comprises: a submerged bearing 30 comprising a cylindrical bearing casing 31 surrounding a rotating shaft 23, and a sliding contact member 36, and rotatably supporting the rotating shaft 23 in a pump casing 15; a closed liquid passage 41 including a protection pipe 42 surrounding the rotating shaft 23, and sealing the sliding contact member 36 and lubricating liquid with respect to water pumping in the pump casing 15; a liquid passage hole 51 for establishing communication between an upper portion and a lower portion of the sliding contact member 36 in the closed liquid passage 41; and a blade 53 attached to the rotating shaft 23 so as to be adjacent to the sliding contact member 36 in the closed liquid passage 41, and circulating the lubricating liquid by rotating integrally with the rotating shaft 23.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vertical pump. [Background technology]

[0002] The vertical pump disclosed in Patent Document 1 is equipped with a protection mechanism that seals (isolates) the submersible bearings from the pumped water and cools and lubricates them with lubricating water to prevent damage to the submersible bearings due to foreign matter contained in the pumped water. This protection mechanism is equipped with a closed circulating water passage including a bearing casing for the submersible bearings, a protective pipe surrounding the rotating shaft, and external piping arranged outside the pump casing, and impellers for circulating the lubricating liquid. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4709878 Summary of the Invention [Problem to be solved by the invention]

[0004] The protection mechanism of Patent Document 1 is large-scale because it is necessary to return the lubricating liquid from the lower part to the upper part of the pump casing through an external pipe. Therefore, the protection mechanism of Patent Document 1 has room for improvement in terms of simplifying the structure.

[0005] An object of the present invention is to simplify the protection mechanism for underwater bearings used in vertical pumps. [Means for solving the problem]

[0006] One aspect of the present invention provides a vertical pump having a pump casing extending in the vertical direction, a rotating shaft whose lower part is arranged within the pump casing, a cylindrical bearing casing surrounding the rotating shaft, and a sliding member attached to a portion of the bearing casing facing the rotating shaft, the liquid bearing rotatably supporting the rotating shaft within the pump casing, a protective tube having at least one end connected to the bearing casing and surrounding the rotating shaft, the lower end of which is shaft-sealed to seal the sliding member and lubricating liquid against pumped water within the pump casing, a liquid passage hole provided in a portion of the bearing casing other than the portion through which the rotating shaft passes, the liquid passage hole connecting an upper portion and a lower portion of the sliding member in the closed liquid passage, and a vane attached to the rotating shaft so as to be adjacent to the upper or lower side of the sliding member within the closed liquid passage, and rotating integrally with the rotating shaft to circulate the lubricating liquid through the liquid passage hole and between the sliding member and the rotating shaft.

[0007] The closed liquid passage includes a protective tube having at least one end connected to the bearing casing, and seals the sliding member and the lubricating liquid against the pumped water in the pump casing. The cylindrical bearing casing to which the protective tube is connected is provided with a liquid passage hole that communicates the upper and lower parts of the sliding member, and a vane that circulates the lubricating liquid is attached to the rotating shaft in the closed liquid passage so as to be adjacent to the sliding member. As a result, the lubricating liquid in the closed liquid passage is circulated through the liquid passage hole and between the sliding member and the rotating shaft in the local area where the bearing casing is arranged. Therefore, the sliding members constituting the submerged bearing can be reliably cooled and lubricated while being protected from foreign matter contained in the pumped water. In addition, since there is no need to arrange external piping on the outside of the pump casing, the protection mechanism of the submerged bearing used in the vertical pump can be simplified. Effect of the Invention

[0008] The present invention can simplify the protection mechanism for the submerged bearings used in the vertical pump. [Brief description of the drawings]

[0009] [Figure 1]FIG. 1 is a cross-sectional view of a vertical pump according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of part II in FIG. [Diagram 3] FIG. 2 is an enlarged cross-sectional view of part III in FIG. [Figure 4] FIG. 2 is an enlarged cross-sectional view of part IV in FIG. 1 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] Referring to FIG. 1, a vertical pump 10 according to an embodiment of the present invention includes a pump casing 15, a rotating shaft 23, an impeller 26, and a submerged bearing (submerged bearing) 30, and discharges water that flows into a suction tank 1 to the downstream side.

[0012] A protection mechanism 40 is provided in the vertical pump 10 of this embodiment to prevent damage to the submersible bearing 30 due to foreign matter such as sand, dirt, and impurities contained in the pumped water. This protection mechanism 40 includes the sliding member 36 of the submersible bearing 30, a closed water passage (closed liquid passage) 41 that seals (isolates) the lubricating liquid from the pumped water, and a circulation mechanism 50 for locally circulating the lubricating liquid within the closed water passage 41. In this embodiment, fresh water is used as the lubricating liquid. However, the lubricating liquid may be oil, or may be an antifreeze liquid containing an additive.

[0013] The configurations of the vertical pump 10 and the protection mechanism 40 will be specifically described below.

[0014] (Vertical pump configuration) Referring to FIG. 1, the vertical pump 10 comprises a cylindrical pump casing 15 extending in the vertical direction, a rotating shaft 23 partially disposed within the pump casing 15, and an impeller 26 attached to the lower end of the rotating shaft 23.

[0015] The pump casing 15 is inserted from above into a mounting hole formed in the installation floor 2 that covers the upper part of the suction tank 1, and is fixed to the installation floor 2. This pump casing 15 includes a lifting pipe 16 and a discharge pipe 20 connected to the upper end of the lifting pipe 16.

[0016] The lift pipe 16 protrudes vertically downward from the installation floor 2. The lift pipe 16 includes a straight pipe 17 of uniform diameter, an elliptical cylindrical vane casing 18 that bulges outward in the radial direction, and a bell mouth 19 that gradually widens toward the lower end. The straight pipe 17, vane casing 18, and bell mouth 19 are joined from top to bottom in this order. The number of straight pipes 17 depends on the total length required for the pump casing 15.

[0017] The discharge pipe 20 is a bent pipe that is bent at approximately 90 degrees, and protrudes upward from the installation floor 2. A water supply pipe (not shown) that is piped to a discharge tank on the downstream side is connected to the discharge pipe 20 via a gate valve (not shown) that can open and close the flow path.

[0018] The rotating shaft 23 has a lower part that passes through the discharge pipe 20 and is disposed inside the lift pipe 16, and an upper part that protrudes outward from the discharge pipe 20. The lower part of the rotating shaft 23 extends in the vertical direction along the axis of the lift pipe 16. A driving source such as an electric motor or prime mover (not shown) is mechanically connected to the upper part of the rotating shaft 23.

[0019] The impeller 26 is attached to the lower end of the rotating shaft 23. The impeller 26 rotates together with the rotating shaft 23 by the rotation of the electric motor (clockwise as viewed from above). As a result, water in the suction tank 1 is sucked in from the suction port at the lower end of the lifting pipe 16 and discharged downstream through the lifting passage 27 in the pump casing 15.

[0020] Continuing to refer to Figure 1, the underwater bearing 30 rotatably supports the rotating shaft 23 within the pump casing 15. The underwater bearings 30 are disposed at both the upper and lower parts of the pump casing 15. Here, the upper part of the pump casing 15 means the part above the vane casing 18, i.e., the part formed by the straight pipe 17. Additionally, the lower part of the pump casing 15 means the part below the straight pipe 17, i.e., the part formed by the vane casing 18 and the bellmouth 19.

[0021] The number of underwater bearings 30 is determined by the overall length of the pump casing 15. When the overall length of the pump casing 15 is short, one or more underwater bearings 30 are arranged in the vane casing 18, and none are arranged in the straight pipe 17. When the overall length of the pump casing 15 is long, one or more are arranged in the straight pipe 17, and one or more are arranged in the vane casing 18. In the pump casing 15 of this embodiment, two underwater bearings 30 are arranged in the straight pipe 17, and two are arranged in the vane casing 18. In the following description, of the three underwater bearings 30, the two arranged in the straight pipe 17 may be referred to as underwater bearings 30A, and the two arranged in the vane casing 18 may be referred to as underwater bearings 30B.

[0022] 2 and 3, both of the underwater bearings 30A, 30B include a bearing casing 31 and a sliding member 36, and rotatably support the rotating shaft 23 via the sleeve 24. The basic configuration of the sleeve 24 and the sliding member 36 is common to the upper underwater bearing 30A and the lower (lower end) underwater bearing 30B. The bearing casing 31 of the upper underwater bearing 30A differs from that of the lower underwater bearing 30B. In the following description, the casing of the underwater bearing 30A may be referred to as the bearing casing (first bearing casing) 31A, and the casing of the underwater bearing 30B may be referred to as the bearing casing (second bearing casing) 31B.

[0023] Hereinafter, the configurations of the sleeve 24, the sliding contact member 36, and the bearing casing 31 will be specifically described in this order with reference to Figs.

[0024] Sleeve 24 is a cylindrical body made of resin that is arranged in close contact with the outer periphery of rotating shaft 23 and is attached to rotating shaft 23 by, for example, a key (not shown) so as to be unable to rotate relative to rotating shaft 23, and rotates integrally with rotating shaft 23. Sleeve 24 used in bearing casing 31A and sleeve 24 used in bearing casing 31B differ only in their overall lengths.

[0025] The sliding contact member 36 is cylindrical, attached to the inner periphery of the bearing casing 31, and rotatably supports the rotating shaft 23 via the sleeve 24. In this embodiment, the sliding contact member 36 is made of hard rubber with excellent abrasion resistance, and is attached to the bearing casing 31 via a metal substrate 37. However, the sliding contact member 36 may be made of resin, ceramic, or metal such as Oiles metal. Only one sliding contact member 36 is arranged in the upper underwater bearing 30A shown in FIG. 2, and two sliding contact members 36 are arranged at an interval in the lower underwater bearing 30B shown in FIG. 3.

[0026] 1 and 2, the bearing casing 31A of the underwater bearing 30A has a cylindrical main body 32 that surrounds the sleeve 24 at a distance, and a sliding member 36 is fixed to the inner periphery of this main body 32. The bearing casing 31A is fixed to the straight pipe 17 via multiple support arms 33 that are plate-shaped and protrude radially from the main body 32.

[0027] 1 and 3, the bearing casing 31B of the underwater bearing 30B has a cylindrical main body 32 like the bearing casing 31A, and two sliding members 36 are fixed to the inner periphery of the main body 32. The bearing casing 31B also has a support part 34 surrounding the main body 32, and is fixed to the vane casing 18 via a plurality of plate-like support arms 33 that protrude radially from the support part 34. The support part 34 is an elliptical cylinder with an open lower end that is connected to the upper end of the main body 32, and rotatably supports the impeller 26 attached to the lower end of the rotating shaft 23. The lower part of the main body 32 and the lower part of the support part 34 are connected by a plurality of ribs 35 that extend radially.

[0028] (Protection mechanism configuration) 1, the protection mechanism 40 is provided to seal (isolate) the sliding contact member 36 of the underwater bearing 30 from the pumped water in the pumping passage 27 and to cool and lubricate it with lubricating water. The protection mechanism 40 includes a closed water passage 41 for sealing the rotating shaft 23 and the sliding contact member 36, and a circulation mechanism 50 for locally circulating the lubricating liquid.

[0029] The closed water passage 41 is provided to prevent foreign matter contained in the pumped water from entering between the sliding contact member 36 and the sleeve 24. This closed water passage 41 is composed of multiple (three in this embodiment) protective pipes 42 and the main body 32 provided in the bearing casing 31. The upper and lower ends of the closed water passage 41 are each sealed by a mechanical seal (shaft seal device) 46. However, the shaft seal device can be changed as necessary as long as it is configured to be able to close the closed water passage 41.

[0030] The protective pipe 42 is a cylinder having an outer diameter spaced apart from the lifting pipe 16 and the rotating shaft 23, and surrounding the rotating shaft 23. In this embodiment, the protective pipes 42 are disposed at three locations, namely, between the penetrating portion 20a of the discharge pipe 20 through which the rotating shaft 23 penetrates and the uppermost bearing casing 31A, and between the vertically adjacent bearing casings 31. Hereinafter, of the three protective pipes 42, the one located at the upper level may be referred to as protective pipe 42A, the one located at the middle level as protective pipe 42B, and the one located at the lower level as protective pipe 42C.

[0031] 1 to 4, the upper end of each protective pipe 42 is liquid-tightly connected to the member to be connected via a seal member 43. Specifically, the upper end of the upper protective pipe 42A is connected to the cylindrical through-hole 20a of the discharge pipe 20, and the upper ends of the other protective pipes 42B, 42C are each liquid-tightly connected to the lower part of the main body 32 of the bearing casing 31A. The lower end of each protective pipe 42 is liquid-tightly connected to the upper end of the main body 32 of the bearing casing 31 via a connection member 44.

[0032] The internal spaces of the multiple protective pipes 42 are each connected to each other via the internal space of the main body 32 of the bearing casing 31. Therefore, the rotating shaft 23 located inside these is surrounded by the protective pipes 42 and the bearing casing 31, and is not exposed at all in the pumping passage 27. The pumping passage 27 is made up of the space between the protective pipes 42 and the straight pipe 17, the space between the bearing casing 31A and the straight pipe 17, the space between the bearing casing 31B and the vane casing 18, and the space inside the bellmouth 19.

[0033] 1 and 4, a connecting pipe 45 is liquid-tightly connected to the upper end of the through-hole 20a of the discharge pipe 20, and a mechanical seal 46 arranged above the connecting pipe 45 seals the upper end of the closed water passage 41 and the rotating shaft 23. Referring to Figs. 1 and 3, a mechanical seal 46 is arranged at the lower end of the main body 32 of the bearing casing 31B, and the mechanical seal 46 seals the lower end of the closed water passage 41 and the rotating shaft 23.

[0034] 1 and 4, a water tank (liquid tank) 47 for refilling the lubricating liquid is connected via a pipe 48 to the closed water passage 41 thus configured.

[0035] The water tank 47 is an elevated water tank located above the connecting pipe 45 and storing replenishment lubricating liquid, and is provided to keep the closed water passage 41 filled with lubricating liquid.

[0036] The upper end of the pipe 48 is connected to the water tank 47, and the lower end of the pipe 48 is branched and connected to the connection pipe 45 which is the upper end of the closed water passage 41. An opening / closing valve 49 is interposed in this pipe 48 and can be switched between an open state in which the water tank 47 and the closed water passage 41 are in communication with each other, and a closed state in which communication between the water tank 47 and the closed water passage 41 is blocked. This opening / closing valve 49 may be either an electric type or a manual type.

[0037] 1, a circulation mechanism 50 is provided for each of the submersible bearings 30, and circulates lubricating liquid around each of the submersible bearings 30 to cool and lubricate the sliding contact members 36. With reference to FIGS. 2 and 3, the circulation mechanism 50 includes a water passage hole (liquid passage hole) 51 provided in the bearing casing 31, and a vane 53 disposed in the closed water passage 41 adjacent to the sliding contact members 36.

[0038] The water passage hole 51 is provided in the closed water passage 41 to communicate the upper and lower parts of the sliding contact member 36. This water passage hole 51 is provided in the main body 32, which is the part of the bearing casing 31 other than the part through which the rotating shaft 23 passes, and penetrates in the vertical direction. Two or more water passage holes 51 are provided at intervals in the circumferential direction. The number and inner diameter of the water passage holes 51 are set according to the circulating flow rate of the lubricating liquid required for cooling and lubricating the sliding contact member 36. In other words, the number of water passage holes 51 may be only one, or may be three or more.

[0039] A water reservoir section (liquid reservoir section) 51a that is recessed radially outward from the inner circumferential surface of the bearing casing 31 is provided in the vertical middle section of the water passage hole 51. This water reservoir section 51a is composed of an annular space, and the open inner circumferential section is closed by the base material 37 of the sliding contact member 36. The water reservoir section 51a is provided in only one location in the bearing casing 31A shown in Fig. 2, and in two locations spaced apart vertically in the bearing casing 31B shown in Fig. 3.

[0040] 1 and 2, a recess 52 for arranging the vanes 53 is provided at the upper end of the bearing casing 31A. The recess 52 is recessed downward from the upper end surface and expands in the radial direction with an inner diameter larger than the outer diameter of the vanes 53. With reference to FIGS. 1 and 3, the connection portion 42a of the protective tube 42C connected to the bearing casing 31B expands radially outward more than other portions of the protective tube 42C in order to arrange the vanes 53. The recess 52 and the connection portion 42a are formed with a diameter that positions a plurality of water passage holes 51 inside when viewed from above. In other words, the water passage holes 51 are provided so as to be positioned within the recess 52 and the connection portion 42a when viewed from above.

[0041] The vanes 53 are attached to the rotating shaft 23 within the closed water passage 41, and rotate integrally with the rotating shaft 23 to circulate the lubricating liquid through the water passage hole 51 and between the sliding contact member 36 and the sleeve 24 (rotating shaft 23). The vanes 53 are disposed in the recess 52 adjacent to the upper side of the sliding contact member 36 in the bearing casing 31A shown in Fig. 2, and are disposed in the connection part 42a adjacent to the upper side of the sliding contact member 36 in the bearing casing 31B shown in Fig. 3.

[0042] 2 and 3, the blade 53 is a centrifugal type that sends out the lubricating liquid from the inside to the outside in the radial direction by rotation. The blade 53 includes a disk-shaped base portion 53a fixed to the rotary shaft 23, a cylindrical outer peripheral portion 53b protruding downward from the outer periphery of the base portion 53a, and a plurality of water supply holes (liquid supply holes) 53c provided at intervals in the circumferential direction on the outer peripheral portion 53b. However, the blade 53 may be configured as a mixed flow impeller or a vortex flow impeller, and may be configured to send out the lubricating liquid from the inside to the outside in the radial direction by rotation.

[0043] Next, local circulation of the lubricating liquid by the circulation mechanism 50 will be described.

[0044] First, when the vertical pump 10 shown in FIG. 1 is stopped, the closed water passage 41 is filled with lubricating liquid by opening the on-off valve 49, and then the on-off valve 49 is closed to provide still water.

[0045] 2 and 3, when the vertical pump 10 is operated for discharging, the impeller 53 rotates due to the rotation of the rotary shaft 23, and the lubricating liquid inside the impeller 53 is sent outward in the radial direction. As a result, around the impeller 53 in the closed water passage 41, the pressure outside the impeller 53 in the radial direction becomes higher than the pressure inside the impeller 53.

[0046] A part of the lubricating liquid discharged by the vanes 53 flows through the water passage hole 51 to the lower side of the bearing casing 31. At this time, a water reservoir portion 51a is provided in the middle portion of the water passage hole 51, so that the lubricating liquid can come into contact with the base material 37 that holds the sliding contact member 36. As a result, the heat of the sliding contact member 36 generated by friction with the sleeve 24 (rotating shaft 23) is absorbed by the lubricating liquid via the base material 37.

[0047] The lubricating liquid located below the bearing casing 31 flows upward between the sliding contact member 36 and the sleeve 24 because the radially inner side of the blades 53 is under negative pressure due to the rotation of the blades 53. Therefore, the sliding contact member 36 can be reliably cooled and lubricated.

[0048] Here, the lubricating liquid in the closed water passage 41 that circulates due to the rotation of the blades 53 is only a portion located around the bearing casing 31, and most of the lubricating liquid located in the middle part of the protective tube 42 is hardly affected by the rotation of the blades 53. On the other hand, the heat absorbed by the lubricating liquid due to circulation is heat exchanged or convected due to the temperature difference with the non-circulating lubricating liquid, and is heat exchanged (cooled) by the pumped water in the pumping passage 27. As a result, the sliding contact members 36 can be reliably cooled and lubricated during the drainage operation.

[0049] The underwater bearing 30 configured as above has the following features.

[0050] The closed water passage 41 includes a protective tube 42, at least one end of which is connected to the bearing casing 31, and seals the sliding member 36 and the lubricating liquid against the pumped water in the pump casing 15. The cylindrical bearing casing 31 to which the protective tube 42 is connected is provided with a water passage hole 51 that connects the upper and lower parts of the sliding member 36, and a vane 53 that circulates the lubricating liquid is attached to the rotating shaft 23 in the closed water passage 41 so as to be adjacent to the sliding member 36. As a result, the lubricating liquid in the closed water passage 41 is circulated through the water passage hole 51 and between the sliding member 36 and the rotating shaft 23 in the local area where the bearing casing 31 is located. Therefore, the sliding member 36 that constitutes the underwater bearing 30 can be reliably cooled and lubricated while being protected from foreign matter contained in the pumped water. In addition, since the lubricating liquid is filled in a closed water passage 41 with its lower end sealed, there is no need to place external piping on the outside of the pump casing 15, and the protection mechanism 40 for the submersible bearing 30 used in the vertical pump 10 can be simplified.

[0051] The vanes 53 are of a centrifugal type that delivers the lubricating liquid from the inside to the outside in the radial direction. This allows the lubricating liquid to be delivered from the inside to the outside in the radial direction of the vanes 53, flow in the vertical direction through the water passage holes 51 of the bearing casing 31, and reliably circulate through the space between the rotating shaft 23 and the sliding contact member 36 on the radial inside of the vanes 53 that is under negative pressure.

[0052] The water passage hole 51 extends radially outward from the inner circumferential surface of the main body 32 of the bearing casing 31, and includes a water reservoir portion 51a closed by the sliding contact member 36. This allows the sliding contact member 36 to be cooled from the outer surface side by the lubricating liquid flowing inside the water passage hole 51, so that the sliding contact member 36 can be effectively cooled.

[0053] A recess 52 for arranging the vanes 53 is provided at the upper or lower end of the bearing casing 31. Alternatively, the vanes 53 are arranged in a connection portion 42a that is expanded more than other portions of the protective tube 42. This simplifies the configuration of the circulation mechanism 50 that locally circulates the lubricating liquid.

[0054] Protective pipes 42 are connected to the upper and lower ends of the bearing casing 31A of the submersible bearing 30A arranged in the upper part of the pump casing 15. This makes it possible to fill the closed water passage 41 with lubricating liquid even in a configuration in which further submersible bearings 30A, 30B are arranged below the upper submersible bearing 30A.

[0055] A mechanical seal 46 that seals the closed water passage 41 is disposed at the lower end of the bearing casing 31B of the submerged bearing 30B disposed at the bottom of the pump casing 15. This prevents leakage of the lubricating liquid from the closed water passage 41 and ensures that the closed water passage 41 is filled with the lubricating liquid.

[0056] A water tank 47 for refilling the closed water passage 41 with lubricating liquid is connected to the upper end of the closed water passage 41. This makes it possible to reliably maintain the closed water passage 41 filled with the lubricating liquid.

[0057] The present invention is not limited to the configurations of the above-described embodiments, and various modifications are possible.

[0058] For example, if the upper end of the closed water passage 41 is located outside the pump casing 15, it may be open and not be sealed by the mechanical seal 46. Also, the closed water passage 41 may be configured to be refilled with lubricating liquid without providing the water tank 47.

[0059] The water passage hole 51 that connects the upper part and the lower part of the sliding contact member 36 in the closed water passage 41 may not have the water reservoir portion 51a in the middle part.

[0060] The vane 53 may be attached to the rotating shaft 23 so as to be adjacent to the lower side of the sliding contact member 36, and the lubricating liquid may flow from the lower side to the upper side of the water passage hole 51.

[0061] In order to accommodate the vanes 53, a recess 52 may be provided at the upper end of the bearing casing 31B, or an expanded connection portion 42a may be provided on the protective tubes 42a, 42B connected to the bearing casing 31A. [Explanation of symbols]

[0062] 1 Water absorption tank 2 Installation floor 10 Vertical pump 15 Pump casing 16. Lifting pipe 17 straight pipe 18 Vane casing 19 Bellmouth 20 Discharge pipe 20a Penetration 23 Rotation axis 24 Sleeve 26 Impeller 27 Pumping Channel 30, 30A, 30B Submerged bearings (submerged bearings) 31 Bearing casing 31A Bearing casing (first bearing casing) 31B Bearing casing (second bearing casing) 32 Main body 33 Support Arm 34 Support part 35 Ribs 36 Sliding contact member 37 Base material 40 Protection mechanism 41 Closed channel (closed liquid channel) 42,42A~42c Protection tube 42a Connection 43 Sealing material 44 Connection parts 45 Connecting pipe 46 Mechanical seal (shaft seal device) 47 Water tank (liquid storage tank) 48 Pipe 49 On-off valve 50 Circulation mechanism 51 Water hole (liquid hole) 51a Water reservoir (liquid reservoir) 52 Recess 53 Feather 53a Circuit board section 53b Outer periphery 53c Water supply hole (liquid supply hole)

Claims

1. A pump casing extending in a vertical direction; A rotating shaft having a lower portion disposed within the pump casing; a submerged bearing including a cylindrical bearing casing surrounding the rotating shaft and a sliding member attached to a portion of the bearing casing facing the rotating shaft, the submerged bearing rotatably supporting the rotating shaft within the pump casing; a closed liquid path including a protective tube having at least one end connected to the bearing casing and surrounding the rotating shaft, the lower end of which is shaft-sealed to seal the sliding member and the lubricating liquid against the pumped water in the pump casing; a liquid passage hole provided in the bearing casing other than a portion through which the rotating shaft passes, the liquid passage hole connecting an upper portion and a lower portion of the sliding contact member in the closed liquid path; a vane attached to the rotating shaft so as to be adjacent to the upper or lower side of the sliding contact member within the closed liquid path, and which rotates integrally with the rotating shaft to circulate the lubricating liquid through the liquid passage hole and between the sliding contact member and the rotating shaft; A vertical pump comprising:

2. 2. The vertical pump according to claim 1, wherein the vanes are of a centrifugal type that deliver the lubricating liquid from the inside to the outside in the radial direction.

3. 3. The vertical pump according to claim 1, wherein the fluid passage hole has a fluid reservoir portion at a vertical intermediate portion, the fluid passage hole being recessed radially outward from an inner circumferential surface of the bearing casing and closed by the sliding contact member.

4. 3. The vertical pump according to claim 1, wherein a recess for arranging the vanes is provided at an upper end or a lower end of the bearing casing so as to be recessed in an axial direction of the rotating shaft and expand in a radial direction.

5. A connection portion of the protective tube that is connected to the bearing casing is expanded more than other portions, The vertical pump according to claim 1 or 2, wherein the impeller is disposed within the connecting portion.

6. Two or more submerged bearings are arranged, the first bearing casing of the submerged bearing disposed in the upper portion of the pump casing has an upper end and a lower end connected to the protective pipes, the second bearing casing of the submerged bearing disposed in the lower portion of the pump casing supports an impeller on its lower side, 3. The vertical pump according to claim 1, further comprising a seal device disposed at a lower end of the second bearing casing for sealing the closed liquid path.

7. 3. The vertical pump according to claim 1, wherein a reservoir tank is connected to an upper end of the closed liquid path for refilling the closed liquid path with the lubricating liquid.

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