JP6595382B2 - Vertical shaft pump - Google Patents

Description

  The present invention relates to a vertical shaft pump.

  2. Description of the Related Art Vertical shaft pumps that reduce the wear of submerged bearings by supplying lubricating water to the submerged bearings in the pump casing are known. In the vertical shaft pump of Patent Document 1, an external water source installed in a pump station and a protective pipe in a pump casing are connected by a water supply pipe, and lubricating water from the external water source is supplied by a water supply pump.

Japanese Patent Laid-Open No. 5-157089

  In the vertical shaft pump of Patent Document 1, it is necessary to connect a long water supply pipe to the pump station, and therefore, if a large impact is applied to the pump station due to an earthquake or the like, there is a high possibility that the water pipe will be damaged. In this case, since the lubricating water cannot be supplied to the underwater bearing, when the operation of the vertical shaft pump is started, the underwater bearing is damaged due to wear, and the pump cannot be operated. Even when a non-water-filled bearing is used as the submersible bearing, when pumped water containing a large amount of slurry is fed, abrasive wear occurs in the non-water-filled bearing, so that the pump cannot be operated.

  An object of the present invention is to provide a vertical shaft pump that can be operated by supplying purified water separated from discharged pumped water as lubricating water to an underwater bearing.

  The present invention has a pump casing having a pumping pipe arranged to extend in the vertical direction, a rotating shaft arranged in the pump casing along an axis of the pumping pipe, and a hollow hub, An impeller connected to the lower end side of the rotating shaft, an underwater bearing disposed in the pumping pipe so as to be positioned above the impeller, and rotatably supporting the rotating shaft, and disposed in the pump casing A protective pipe that covers the outer periphery of the rotating shaft, and is provided in the hub, and a part of the pumped water sucked into the pumping flow path between the pump casing and the protective pipe is taken in A cyclone separator that separates pumped water into purified water and sewage, supplies the purified water to the underwater bearing by supplying the purified water into the protective tube, and causes the sewage to flow into the pumped water flow path. Obtain, to provide a vertical shaft pump.

According to this vertical shaft pump, since the purified water separated from the pumped water by the cyclone separator is supplied to the underwater bearing as lubricating water, the wear of the underwater bearing can be suppressed. Further, since the cyclone separator hub of the impeller is provided, an external water source and piping required have for water supply to the pump station is incidental facilities. Therefore, it is possible to prevent the pump from becoming inoperable due to a large impact caused by an earthquake or the like and only the water supply pipe being damaged. Moreover, since a water supply pipe is not required, the space for the pump station can be saved and the degree of freedom in design and production can be improved. Furthermore, the cyclone separator is configured to discharge sewage containing slurry and the like to the external pumping flow path, and is not clogged compared with the case of using filtering means consisting of a filter. The number of times can be reduced.

The vertical shaft pump may include a casing hub that is fixed to the pumping pipe so as to cover an upper portion of the hub . In this case, the protective tube so as to extend upwardly from the casing hub and is arranged, the water purification through the casing hub is supplied to the protective tube. According to this aspect, the purified water separated by the cyclone separator can be supplied to all the underwater bearings, and damage to the underwater bearings can be prevented.

An inflow port for allowing the pumped water in the pumping flow path to flow into the cyclone separator is provided at a lower portion of the casing hub , and an outlet for discharging the dirty water into the pumped water flow path is provided in the hub. Good. And it is preferable that the said inflow port is opened so that it may oppose with respect to the rotation direction of the said impeller. According to this aspect, a part of the pumped water sucked into the pumped pipe by the impeller can be reliably taken into the cyclone separator.

  The hub may have a conical shape whose diameter gradually increases from the bottom upward, and the hub may also serve as the conical container of the cyclone separator. According to this aspect, since the swirling speed of the pumped water taken is accelerated by the rotation of the hub, the pumped water can be separated into purified water and sewage with high efficiency.

Alternatively, a conical container of the cyclone separator may be disposed in the hub. In this case, the conical container may be fixed to the casing hub . The hub may have a conical shape having a diameter that gradually increases from the bottom upward, and the conical container may be a protector that protects the back blades protruding from the hub.

  The vertical pump may be provided with a monitoring device for judging an abnormality of the underwater bearing. The monitoring device includes a recovery pipe connected to the protection pipe above the underwater bearing, a flow meter disposed in the recovery pipe and detecting the flow rate of the purified water recovered from the protection pipe; And a determination unit that determines the occurrence of an abnormality in the underwater bearing based on the purified water flow rate detected by the flow meter. According to this aspect, the vertical shaft pump can always be operated in a stable state.

  According to the pump of the present invention, since the purified water separated from the pumped water to be discharged is supplied to the underwater bearing as lubricating water, the steady operation is reliably maintained without damaging the underwater bearing as long as the pump is operable. it can.

Sectional drawing which shows the vertical shaft pump of 1st Embodiment. The expanded sectional view shown in the lower part of FIG. The conceptual diagram of a cyclone separator. FIG. 3 is a cross-sectional view of FIG. 2. The expanded sectional view which shows the 1st underwater bearing of FIG. The expanded sectional view which shows the 2nd underwater bearing of FIG. The expanded sectional view which shows the shaft seal part of FIG. Sectional drawing which shows the lower part of the vertical shaft pump of 2nd Embodiment. Sectional drawing which shows the lower part of the vertical shaft pump of 3rd Embodiment. FIG. 9B is a partially enlarged sectional view of FIG. 9A. FIG. 9B is a cross-sectional view of FIG. 9A. Sectional drawing which shows the lower part of the vertical shaft pump of 4th Embodiment. The partial expanded sectional view of FIG. The top view which shows the wear ring of FIG. FIG. 12 is a cross-sectional view of FIG. 11.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows a vertical shaft pump 10 according to the first embodiment. The vertical shaft pump 10 includes a pump casing 12, a rotating shaft 20, and an impeller 22, and is arranged so as to hang down on the installation floor 1 of the pump station. The vertical shaft pump 10 of the present embodiment includes underwater bearings 27A to 27C that rotatably support the rotary shaft 20 and a protective pipe 56 that covers the outer periphery of the rotary shaft 20, and the protective pipe 56 is separated from a part of the pumped water PW. By supplying the purified water CW, wear of the underwater bearings 27A to 27C is reduced.

  The pump casing 12 includes a cylindrical pumping pipe 13, and the pumping pipe 13 is disposed so as to penetrate the installation floor 1 and extend in the suction water tank 2 in the vertical direction. The pumping pipe 13 includes a vane casing 14 on the lower side. Moreover, a trumpet tube 15 in which a suction port 16 is formed is disposed below the vane casing 14. A discharge elbow 17 is disposed at the upper end of the pumping pipe 13, and a discharge pipe 18 is connected to the discharge elbow 17.

  The rotary shaft 20 passes through the discharge elbow 17 and is disposed in the pump casing 12 along the axis of the water pump 13. The lower end of the rotating shaft 20 is disposed in the vane casing 14. The impeller 22 is connected to the lower end of the rotating shaft 20 so as not to be relatively rotatable so as to be positioned in the vane casing 14. The first and second underwater bearings 27 </ b> A and 27 </ b> B are disposed in the vane casing 14 via the casing hub 40 above the impeller 22. The third underwater bearing 27 </ b> C is disposed in the pumped water pipe 13 through the bearing holder 53 so as to be positioned between the vane casing 14 and the upper end of the pump casing 12.

  In the vertical shaft pump 10, the impeller 22 is rotated through the rotating shaft 20 by driving of a motor 30 as driving means. By this steady operation, the pumped water PW in the suction water tank 2 is sucked from the suction port 16 at the lower end of the pump casing 12, and this pumped water PW is discharged downstream from the pumped water pipe 13 through the discharge elbow 17 and the discharge pipe 18.

  As the first to third submersible bearings 27A to 27C, it is preferable to use non-water-filled bearings made of ceramics or resin that can execute a steady operation even when the supply of lubricating water is cut off. However, even when non-water-filled bearings are used as the underwater bearings 27A to 27C, when draining a liquid containing a large amount of slurry by the vertical shaft pump 10, since abrasive wear occurs in the underwater bearings 27A to 27C, lubricating water is supplied. It is preferable. Therefore, the vertical pump 10 of this embodiment is provided with a water injection mechanism described below.

(Details of water injection mechanism)
Referring to FIG. 1 in conjunction with FIG. 2, the water injection mechanism includes a cyclone separator 32 provided on the impeller 22. The cyclone separator 32 is a filtering means that takes in a part of the pumped water PW discharged by the vertical shaft pump 10 and can separate the pumped water PW into purified water CW and sewage DW. Further, a protective tube 56 that covers the outer periphery of the rotary shaft 20 is disposed inside the pump casing 12 from the lower portion where the impeller 22 is disposed to the upper end of the discharge elbow 17. In the present embodiment, the purified water CW separated by the cyclone separator 32 is supplied into the protective tube 56. That is, the inside of the pump casing 12 of the present embodiment is partitioned into a pumping flow path 65 between the pump casing 12 and the protection pipe 56 and a water purification flow path 66 between the protection pipe 56 and the rotating shaft 20. .

  First, the principle of the cyclone separator 32 is demonstrated using the conceptual diagram of FIG. The cyclone separator 32 includes a conical container 33 formed of a cylindrical body having a diameter that gradually increases from the bottom to the top. The upper end opening of the conical container 33 is closed by a lid member 34. A pumping water inlet 35 is provided on the outer periphery of the conical container 33. A cylindrical sewage outlet 36 is provided at the lower end of the conical container 33, and a cylindrical purified water outlet 37 is provided on the lid member 34.

  The pumped water PW flows into the conical container 33 from the pumped water inlet 35 with the direction in contact with the outer periphery of the conical container 33 as the inflow direction. Then, the pumped water PW swirls along the wall surface of the conical container 33 (see swirl flow RF). Thereby, the pressure near the wall surface of the conical container 33 increases, and the pressure near the central axis of the conical container 33 decreases. Further, in the vicinity of the central axis of the conical container 33, an upward flow UF is generated in the upper part and a downward flow is generated in the lower part.

  The solid matter contained in the pumped water PW is separated from the liquid by centrifugal force due to the swirl flow RF, settles downward while rotating, and is discharged from the waste water outlet 36 to the outside of the conical container 33 as waste water DW. Further, the purified water CW from which the solid matter has been separated is discharged from the purified water outlet 37 to the outside of the conical container 33 by the upward flow UF. However, minute solids that do not cause wear in the underwater bearings 27 </ b> A to 27 </ b> C may be discharged from the purified water outlet 37 on the upward flow UF.

  Such a cyclone separator 32 is provided on the hollow hub 23 of the impeller 22. Referring to FIG. 2 together with FIG. 4, the impeller 22 includes a conical hub 23 having a diameter that gradually increases from the bottom upward, and a plurality of blades 24 that project radially outward from the hub 23. It has. The conical hub 23 serves as the function of the conical container 33 of the cyclone separator 32. The upper end opening of the hub 23 is covered with a casing hub 40. Further, the hub 23 is provided with a boss 23 a for connecting to the rotary shaft 20.

  The casing hub 40 is fixed in the vane casing 14 via guide vanes 41. The casing hub 40 is a cylindrical body having a bottom wall 42 extending in a direction orthogonal to the axis of the rotary shaft 20 at the lower end. The upper end opening of the casing hub 40 is closed by a substantially conical cylindrical closing member 44. Referring to FIG. 2 in combination with FIGS. 4 and 5, the bottom wall 42 is provided with a cylindrical sleeve 43 extending along the rotation shaft 20, and a cylindrical sliding body 28 </ b> A is provided in the sleeve 43. A first underwater bearing 27A provided is arranged. The closing member 44 is provided with a cylindrical sleeve 45 extending along the rotary shaft 20, and a second underwater bearing 27 </ b> B including a cylindrical sliding body 28 </ b> B is disposed in the sleeve 45.

  A lid 47 located at the upper end opening of the hub 23 is fixed to the bottom wall 42 of the casing hub 40. A plurality (four in this embodiment) of inflow pipes 48 are arranged on the lid 47. As shown most clearly in FIG. 4, the inflow pipe 48 is disposed so as to extend in a direction in contact with the outer periphery of the lid body 47. The outer end side of the inflow pipe 48 passes through the side wall of the casing hub 40, and the penetrating portion thereof is sealed in a liquid-tight manner. An inflow port 49 that is an outer end of the inflow pipe 48 is opened in the pumping flow path 65 so as to face the rotation direction A of the impeller 22 shown in FIG. An outlet 50 that is the inner end of the inflow pipe 48 opens above the hub 23. As shown most clearly in FIG. 5, a gap 51 having a set interval is formed between the lid 47 and the rotary shaft 20.

  The lid 47 also functions as the lid member 34 of the cyclone separator 32. In addition, the inflow pipe 48 disposed in the lid body 47 also functions as the pumped water inlet 35 of the cyclone separator 32. The gap 51 between the lid 47 and the rotary shaft 20 also functions as the purified water outlet 37 of the cyclone separator 32. Further, a through hole 25 is provided in the lower peripheral wall of the hub 23, and this through hole 25 also functions as a sewage outlet 36 of the cyclone separator 32.

  When the impeller 22 rotates, the pumped water PW flows toward the discharge elbow 17 while turning in the same direction as the rotation direction A of the impeller 22 in the vane casing 14 of the pumping flow path 65. Thereby, a part of the pumped water PW is taken into the hub 23 from the inlet 49 of the inflow pipe 48 facing the flow direction of the pumped water PW, and swirls along the wall surface of the hub 23. Moreover, since the turning speed of the pumped water PW in the hub 23 is accelerated by the rotation of the hub 23, the pumped water PW can be separated into the purified water CW and the sewage DW with high efficiency.

  The separated purified water CW ascends around the boss 23a of the impeller 22 and flows to the casing hub 40 side through the gap 51. Then, the purified water CW flows into the casing hub 40 through a slight gap between the first underwater bearing 27 </ b> A and the rotary shaft 20. When the inside of the casing hub 40 is filled with the purified water CW, the purified water CW flows out of the casing hub 40 through a slight gap between the second underwater bearing 27 </ b> B and the rotary shaft 20.

  Further, the separated sewage DW flows out to the pumped water flow path 65 through the through hole 25. 1 and 2, the through hole 25 penetrates along the flow direction of the pumped water PW, and the flow direction of the pumped water PW and the outflow direction of the sewage DW are opposite to each other. Here, if the suction port pressure in the trumpet tube 15 is P0, the impeller outlet pressure on the upper side of the vane plate 24 is P1, and the cyclone separator pressure in the hub 23 is P2, the pressure P2 is higher than the pressure P0, The pressure P1 becomes higher than the pressure P2 (P0 <P2 <P1). Accordingly, the pumped water PW does not flow back into the hub 23 through the through hole 25.

  The protective tube 56 is disposed from the casing hub 40 to the upper end of the discharge elbow 17. The protective tube 56 includes a first portion 56a extending from the casing hub 40 to the bearing holder 53, and a second portion 56b extending from the bearing holder 53 to the through hole 17a. The portions 56 a and 56 b of the protective tube 56 communicate with each other through the bearing holder 53.

  Referring to FIG. 2, the lower end of the first portion 56 a of the protective tube 56 is fixed to the casing hub 40 at the upper end of the sleeve 45 where the second underwater bearing 27 </ b> B is disposed. Referring to FIG. 6, the bearing holder 53 is a cylindrical body in which a third underwater bearing 27 </ b> C having a cylindrical sliding body 28 </ b> C is disposed, and is fixed in the pumped water pipe 13 through a guide vane 54. . In the bearing holder 53, the upper end of the first portion 56a of the protective tube 56 is fixed to the lower end, and the lower end of the second portion 56b of the protective tube 56 is fixed to the upper end. Referring to FIG. 7, a cylindrical insertion member 58 is disposed in the through hole 17 a of the discharge elbow 17, and the upper end of the second portion 56 b of the protective tube 56 is fixed to the insertion member 58.

  A set gap is formed between the insertion member 58 and the rotary shaft 20. A shaft seal device 60 that prevents the pumped water PW from flowing out between the pump casing 12 and the rotary shaft 20 is disposed at the upper end of the insertion member 58. The shaft seal device 60 includes a shaft seal casing 61 disposed at the upper end of the insertion member 58. A mechanical seal 62 is disposed on the shaft seal casing 61. Further, the shaft seal casing 61 is provided with a connection portion 63 to which a recovery pipe 68 is connected so as to be positioned below the mechanical seal 62.

  Referring to FIG. 1, the recovery pipe 68 is piped from the connection portion 63 located on the installation floor 1 so as to penetrate the installation floor 1 and the tip reaches the suction water tank 2. The recovery pipe 68 is connected to the protective pipe 56 via the shaft seal device 60 on the upper side, which is downstream of the submerged bearings 27A to 27C in the direction in which the purified water CW flows. In the present embodiment, the thrust bearing 70 can be cooled by the purified water CW by passing through the thrust bearing 70 disposed in a portion protruding from the shaft seal device 60. However, the purified water CW may be discharged directly to the suction water tank 2 without passing through the thrust bearing 70.

  The purified water CW separated by the cyclone separator 32 flows from the casing hub 40 into the first portion 56a of the protective tube 56, and then a slight gap between the third underwater bearing 27C in the bearing holder 53 and the rotary shaft 20. And flows into the second portion 56 b of the protective tube 56. Next, the purified water CW flows into the shaft seal casing 61 through the insertion member 58 and flows out of the pump casing 12 from the connection portion 63. Thereafter, the purified water CW passes through the recovery pipe 68 and cools the thrust bearing 70, and is then returned to the suction water tank 2.

  Here, if the purified water flow path pressure in the protective pipe 56 is P3 and the atmospheric pressure in the suction water tank 2 is P4, the pressure P3 is higher than the atmospheric pressure P4, and the pressure P2 is higher than the pressure P3 (P0 <P4). <P3 <P2 <P1). Therefore, the purified water CW flowing out from the cyclone separator 32 is reliably returned to the suction water tank 2 through the casing hub 40, the protective pipe 56, and the recovery pipe 68.

  Thus, in the vertical shaft pump 10 of this embodiment, since the purified water CW separated by the cyclone separator 32 is supplied to the underwater bearings 27A to 27C through the protective tube 56, wear of the underwater bearings 27A to 27C can be suppressed. Moreover, since the cyclone separator 32 is provided in the hub 23 of the impeller 22, an external water source and water supply pipes which are incidental facilities are not necessary in the pump station. Therefore, even when a large impact is applied due to an earthquake or the like, it is possible to prevent the vertical pump 10 from becoming inoperable due to the incidental equipment being damaged.

  In addition, since large-scale incidental facilities such as an external water source and a long water supply pipe are not necessary, the space for the pump station can be saved and the degree of freedom in design can be improved. Furthermore, since the cyclone separator 32 is not clogged with slurry or the like as compared with a filtering means made of a filter, the number of maintenance inspections of the equipment can be reduced. Further, since the separated sewage DW is returned to the pumping flow path 65 in the pump casing 12 and drained to the downstream side together with the pumped water PW, an incidental facility for processing the sewage DW is not necessary.

  Moreover, the period (life) which can use the vertical shaft pump 10 becomes long by supplying the purified water CW and reducing wear of the underwater bearings 27A to 27C. However, since the underwater bearings 27 </ b> A to 27 </ b> C are in sliding contact with the rotating shaft 20, it is impossible to completely eliminate wear. Therefore, the gap between the underwater bearings 27A to 27C and the rotary shaft 20 gradually increases with use. In order to detect such abnormalities in the underwater bearings 27A to 27C, the vertical pump 10 of the present embodiment is provided with a monitoring device described below.

(Details of monitoring device)
The monitoring device includes a flow meter 72 that detects the flow rate of the purified water CW recovered from the protective tube 56. The flow meter 72 is disposed in the recovery pipe 68 above the installation floor 1 so as to be positioned between the shaft seal device 60 and the thrust bearing 70. In addition, a gate valve 74 is disposed between the shaft seal device 60 and the flow meter 72 in the recovery pipe 68. Further, a check valve 76 is disposed in the recovery pipe 68 downstream of the thrust bearing 70 in the direction in which the purified water CW flows. By opening and closing the check valve 76, the recovery pipe 68 can be communicated or blocked.

  In addition, the monitoring device includes a determination unit that determines the occurrence of abnormality in the underwater bearings 27 </ b> A to 27 </ b> C based on the purified water flow rate detected by the flow meter 72. The function of this determination unit also functions as a control device 78 that controls the motor 30 based on a command from an operation panel (not shown) and executes the above-described steady operation. The control device 78 performs the inspection operation in parallel with the steady operation.

  As described above, the purified water CW separated by the cyclone separator 32 is collected in the collection pipe 68 through the gap between the underwater bearings 27 </ b> A to 27 </ b> C and the rotary shaft 20. That is, the flow rate of the purified water CW flowing through the gap between the underwater bearings 27 </ b> A to 27 </ b> C and the rotary shaft 20 corresponds to the purified water flow rate detected by the flow meter 72. There is little clearance between the case where the wear is small and the gap between the underwater bearings 27A to 27C and the rotating shaft 20 is small, and the case where the wear is advanced and the gap between the underwater bearings 27A to 27C and the rotating shaft 20 is increased. Larger water flow increases.

  In the control device 78 as the determination unit, the purified water flow rate Ra in a state where preparation for replacement is necessary and the purified water flow rate Rb in a state where replacement is necessary are stored as determination values. And the control apparatus 78 can determine abnormality of the underwater bearings 27A-27C by comparing the detection value R by the flowmeter 72 with the determination values Ra and Rb.

  Thus, in the vertical shaft pump 10 of the present embodiment, the water flow rate collected from the protective tube 56 is detected by the flow meter 72, whereby the abnormality of the underwater bearings 27A to 27C can be determined. Then, by replacing the underwater bearings 27A to 27C by determining the abnormality, the steady operation can always be executed in a stable state, so that the reliability of the vertical pump 10 can be improved.

(Second Embodiment)
FIG. 8 shows a vertical shaft pump 10 according to the second embodiment. This second embodiment is different from the first embodiment in that a conical container 80 separate from the hub 23 is disposed in the hub 23 of the impeller 22 as the conical container 33 of the cyclone separator 32. In addition, the same structure as 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits detailed description.

  The diameter of the conical container 80 is gradually increased from the lower part to the upper part, and the upper end of the conical container 80 is connected to the outer peripheral part of the lid 47. The lid body 47 is connected to the bottom wall 42 of the casing hub 40 as in the first embodiment. That is, in the second embodiment, a fixed conical container 80 that does not rotate together with the impeller 22 is disposed inside the hub 23. An inflow pipe 48 is disposed at a portion where the upper end of the conical container 80 and the outer periphery of the lid body 47 intersect as in the first embodiment. An opening 81 is provided at the lower end of the conical container 80, and the inside of the conical container 80 and the hub 23 communicate with each other through the opening 81.

  In the second embodiment, when the impeller 22 rotates, the pumped water PW swirls in the same direction as the rotation direction A of the impeller 22 in the vane casing 14 of the pumping flow path 65, as in the first embodiment. Part of the PW is taken into the conical container 80 through the inlet tube 48. The pumped water PW is separated into purified water CW and sewage DW by swirling along the wall surface of the conical container 80.

  The separated purified water CW flows into the casing hub 40 through the gap between the first underwater bearing 27A and the rotating shaft 20 and then the second underwater bearing 27B and the rotating shaft 20 as in the first embodiment. It flows into the pumping pipe 13 through the gap. Then, it is returned to the suction water tank 2 through the recovery pipe 68. Further, the separated sewage DW flows out of the conical container 80 through the opening 81, and flows out from the through hole 25 of the impeller 22 to the pumping flow path 65.

  As described above, the conical container 80 constituting the cyclone separator 32 may be a fixed type that does not rotate together with the impeller 22. And even if it does in this way, the effect | action and effect similar to 1st Embodiment can be acquired.

(Third embodiment)
FIG. 9A shows the vertical shaft pump 10 of the third embodiment. This third embodiment is different from the first embodiment in that a protector 87 that protects the reinforcing back blade 85 formed on the hub 23 of the impeller 22 is used as the conical container 33 of the cyclone separator 32. To do. In addition, the same structure as 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits detailed description.

  9A and 9B together with FIG. 10, the hub 23 has a conical shape whose diameter gradually increases from the bottom to the top as in the embodiments. A plurality of back blades 85 extending along the axial direction of the rotary shaft 20 are provided on the inner peripheral surface of the hub 23 at intervals in the circumferential direction. The dimension in which each back blade 85 projects from the inner surface of the hub 23 is constant.

  The protector 87 has a conical cylinder shape whose diameter gradually increases from the bottom to the top, and is disposed along the inner end of the back blade 85. The protector 87 has an upper end outer peripheral portion fixed to the casing hub 40. An opening 88 is provided at the lower end of the protector 87, and the inside of the protector 87 and the inside of the hub 23 communicate with each other through this opening 88. A set gap 90 is formed between the protector 87 and the inner surface of the hub 23.

  The casing hub 40 is provided with an inflow hole 92 extending in a direction in contact with the protector 87 so as to be positioned above the upper end of the protector 87. An inflow port 93 that is an outer end of the inflow hole 92 is opened in the pumped water passage 65 so as to face the rotation direction A of the impeller 22. An outflow port 94 that is an inner end of the inflow hole 92 opens above the protector 87.

  The through hole 25 shown in each embodiment is not provided in the hub 23. The gap 90 between the hub 23 and the protector 87 also functions as a drain hole for discharging the sewage DW to the pumping flow path 65. And the clearance gap between the upper end of the hub 23 and the casing hub 40 comprises the sewage outflow port 94 which is an exit of a drain hole.

  In the third embodiment, when the impeller 22 rotates, the pumped water PW turns in the same direction as the rotation direction A of the impeller 22 in the vane casing 14 of the pumped water passage 65, so that a part of the pumped water PW is inflow hole 92. Through the protector 87. The pumped water PW is separated into purified water CW and sewage DW by turning along the wall surface of the protector 87.

  The separated purified water CW flows into the casing hub 40 through the gap between the first submersible bearing 27A and the rotary shaft 20, and then passes through the gap between the second submersible bearing 27B and the rotary shaft 20 to the pumped water pipe. 13 flows in. Then, it is returned to the suction water tank 2 through the recovery pipe 68.

  The separated sewage DW flows out of the protector 87 through the opening 88, and flows out from the sewage outlet 94 to the pumping flow path 65 through the gap 90. Here, the pressure P <b> 1 in the pumping flow path 65 increases as the pressure P <b> 1 is located upward along the axial direction of the rotary shaft 20. The pumped water inlet 93 is provided above the sewage outlet 94. Therefore, in the pumped water flow path 65, if the pressure at the position of the sewage outlet 94 is P1a and the pressure at the position of the pumped water inlet 93 is P1b, the pressure P1b is higher than the pressure P1a (P1a <P1b). Moreover, the cyclone separator pressure P2 in the protector 87 is higher than the sewage outlet pressure P1a (P1a <P2 <P1b). Therefore, the sewage DW flowing out from the protector 87 is surely discharged from the sewage outlet 94 to the pumping flow path 65 through the gap 90.

(Fourth embodiment)
FIG. 11 shows a vertical shaft pump 10 according to the fourth embodiment. The fourth embodiment is different from the first embodiment in that the inlet 49 of the inflow pipe 48 is opened in the hub 23 constituting the conical container 33 of the cyclone separator 23. In addition, the same structure as 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits detailed description.

  Referring to FIG. 12, the hub 23 includes a guide tube 23 b positioned inside a step portion 42 a formed on the bottom wall 42 of the casing hub 40. An impeller wear ring 100 is fixed to the outer peripheral portion of the guide cylinder 23b, and a case wear ring 102 is fixed to the inner peripheral portion of the step portion 42a. The wear rings 100 and 102 are disposed with a gap that suppresses wear caused by sliding contact with each other. A shear groove 101 is formed on the outer peripheral surface of the impeller wear ring 100, and a shear groove 103 is formed on the inner peripheral surface of the case wear ring 102. Referring also to FIG. 13, the shear groove 101 of the impeller wear ring 100 is provided so as to be inclined in the rotation direction of the impeller 22 from the lower end to the upper end of the impeller wear ring 100. The shear groove 103 of the case wear ring 102 is provided so as to be inclined from the lower end to the upper end of the case wear ring 102 in the direction opposite to the rotation direction of the impeller 22. That is, the shear grooves 101 and 103 are inclined in a direction crossing each other.

  Referring to FIGS. 12 and 14, the lid member 34 that closes the upper end opening of the hub 23 has a flat plate shape, and a leakage prevention ring 98 is disposed on the outer peripheral portion. Since the leakage prevention ring 98 is positioned in the vicinity of the inner surface of the guide cylinder 23b, the upper part and the lower part with the lid member 34 as a boundary are partitioned (sealed). The inflow pipe 48 is disposed obliquely with respect to the lid member 34. The inlet 49 of the inflow pipe 48 passes through the lid member 34 and opens between the lid member 34 and the bottom wall 42 so as to face the rotational direction A of the impeller 22. The outlet 50 of the inflow pipe 48 passes through the lid member 34 and opens in the hub 23.

  In the fourth embodiment, when the impeller 22 rotates, a part of the pumped water PW in the pumped water flow path 65 becomes a gap between the wear rings 100 and 102 due to a pressure difference between the inside and the outside of the hub 23 (P2 <P1). And flows into the hub 23. At this time, if foreign matter (for example, string-like foreign matter) is to flow in with the pumped water PW, the foreign matter is sheared by the shear grooves 101 and 103 and flows in a pulverized state. Then, the pumped water PW that has flowed into the hub 23 turns in the same direction as the rotation direction A of the impeller 22, so that the lid member 34 in the hub 23 that forms the conical container 33 from the inlet 49 of the inlet pipe 48. Flows into the bottom of the. The pumped water PW is separated into purified water CW and sewage DW by turning along the wall surface of the protector 87.

  The separated purified water CW flows into the casing hub 40 through the gap between the first submersible bearing 27A and the rotary shaft 20, and then passes through the gap between the second submersible bearing 27B and the rotary shaft 20 to the pumped water pipe. 13 flows in. Then, it is returned to the suction water tank 2 through the recovery pipe 68. Further, the separated sewage DW flows out from the through hole 25 of the impeller 22 to the pumping flow path 65. At this time, the foreign matter crushed by the shear grooves 101 and 103 is surely discharged from the hub 23 to the pumping flow path 65 through the through hole 25 of the impeller 22.

  In the fourth embodiment configured as described above, the same operations and effects as those of the first embodiment can be obtained. Moreover, since shear grooves 101 and 103 capable of pulverizing foreign matter are provided on the opposed surfaces of the wear rings 100 and 102 through which the pumped water PW passes, even if foreign matter is mixed in the pumped water PW, the cyclone separator 32 The function is not impaired. Moreover, since the inflow pipe 48 does not penetrate the casing hub 40, the structure of the pump casing 12 can be simplified. Therefore, an increase in manufacturing cost of the vertical shaft pump 10 can be suppressed. Also in the vertical shaft pump 10 of the second embodiment, the inlet 49 of the inflow pipe 48 may be opened in the hub 23 so as not to penetrate the casing hub 40 as in the fourth embodiment.

  The vertical shaft pump 10 of the present invention is not limited to the configuration of the above embodiment, and various modifications can be made.

  For example, the direction in which the inflow pipe 48 and the inflow hole 92 are opened in the pumping flow path 65 is preferably changed as appropriate according to the direction in which the pumped water PW flows in the pumping flow path 65. Further, the protective tube 56 may have a full length that extends only to a portion that does not reach the upper end of the pump casing 12. Further, only two underwater bearings may be arranged in the pumping pipe 13, or four or more underwater bearings may be arranged.

DESCRIPTION OF SYMBOLS 1 ... Installation floor 2 ... Suction water tank 10 ... Vertical shaft pump 12 ... Pump casing 13 ... Pumping pipe 14 ... Vane casing 15 ... Trumpet pipe 16 ... Suction port 17 ... Discharge elbow 17a ... Through-hole 18 ... Discharge pipe 20 ... Rotating shaft 22 ... Impeller 23 ... Hub 23a ... Boss 23b ... Guide cylinder 24 ... Blade plate 25 ... Through hole 27A-27C ... Underwater bearing 28A-28C ... Sliding body 30 ... Motor 32 ... Cyclone separator 33 ... Conical container 34 ... Lid member 35 ... Pumping water Inlet 36 ... Sewage outlet 37 ... Purified water outlet 40 ... Casing hub 41 ... Guide vane 42 ... Bottom wall 42a ... Step part 43 ... Sleeve 44 ... Closure member 45 ... Sleeve 47 ... Lid 48 ... Inlet pipe 49 ... Inlet 50 ... Outlet 51 ... Clearance 53 ... Bearing holder 54 ... Guide vane 56 ... Protective tube 56a ... First part 56b ... 2nd part 58 ... Insertion member 60 ... Shaft seal device 61 ... Shaft seal casing 62 ... Mechanical seal 63 ... Connection part 65 ... Pumping flow path 66 ... Purified water flow path 68 ... Recovery pipe 70 ... Thrust bearing 72 ... Flow meter 74 ... Partition Valve 76 ... Check valve 78 ... Control device 80 ... Conical container 81 ... Opening portion 85 ... Back blade 87 ... Protector 88 ... Opening portion 90 ... Gap 92 ... Inlet hole 93 ... Inlet 94 ... Outlet 96 ... Sewage outlet 98 ... Leakage prevention ring 100 ... Impeller wear ring 101 ... Shear groove 102 ... Case wear ring 103 ... Shear groove

Claims (9)

A pump casing having a pumping pipe arranged to extend in the vertical direction;
A rotating shaft disposed in the pump casing along the axis of the pumping pipe;
An impeller having a hollow hub and connected to a lower end side of the rotating shaft;
An underwater bearing disposed in the pumping pipe so as to be located above the impeller, and rotatably supporting the rotating shaft;
A protective tube disposed in the pump casing and covering the outer periphery of the rotating shaft;
The pump is provided in the hub, and a part of the pumped water sucked into the pumping flow path between the pump casing and the protective pipe is taken to separate the pumped water into purified water and sewage, and the purified water is separated in the protective pipe And a cyclone separator that supplies the purified water to the submersible bearing and causes the dirty water to flow into the pumping flow path. A casing hub that is secured to the riser pipe so as to cover the upper portion of the hub, this is from the casing hub said protective tube is arranged so as to extend upwardly, the water purification is the protection through the casing hub The vertical shaft pump according to claim 1, which is supplied into a pipe. An inlet for allowing the pumped water in the pumping flow path to flow into the cyclone separator is provided at a lower portion of the casing hub , and an outlet for discharging the dirty water into the pumped water flow path is provided in the hub. The vertical shaft pump according to claim 2.   The vertical pump according to claim 3, wherein the inflow port is open so as to face the rotation direction of the impeller.   The vertical shaft pump according to any one of claims 1 to 4, wherein the hub has a conical shape whose diameter gradually increases from the bottom upward, and the hub also serves as a conical container of the cyclone separator. .   The vertical shaft pump according to any one of claims 1 to 4, wherein a conical container of the cyclone separator is disposed in the hub. The vertical shaft pump according to claim 6, wherein the conical container is fixed to the casing hub . The hub has a conical shape whose diameter gradually increases from the bottom to the top,
The vertical shaft pump according to claim 6 or 7, wherein the conical container is a protector that protects a back blade protruding from the hub. A recovery pipe connected to the protective pipe above the underwater bearing;
A flow meter arranged in the recovery pipe and detecting the flow rate of the purified water recovered from the protective pipe;
A vertical shaft pump according to any one of claims 1 to 8, further comprising: a determination unit that determines occurrence of abnormality of the underwater bearing based on a purified water flow rate detected by the flow meter.

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