JP2006233786A - Vertical shaft type pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vertical shaft type pump 10 being suitable for preceding stand-by operation using a bearing 1 having excellent resistance to wear even if operation time in air without pouring water is long and bearings 2, 3 capable of withstanding load due to vibration at air lock operation time sufficiently. <P>SOLUTION: A pump shaft 40 is supported by the bearings 1, 2, 3 on the upstream side and the downstream side of an impeller 41 in a pump flow passage. A sliding member of the bearing 1 arranged on the upstream side is formed by a ringlike square braid packing made of aramid fibers having excellent resistance to wear for non-water pouring operation and polytetrafluoroethylene-graphite compound fibers. Sliding members of the bearings 2, 3 arranged on the downstream side are formed by a composite material made of polyether etherketone having excellent resistance to load for vibration by air lock operation and carbon fibers. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vertical shaft pump capable of performing a preliminary standby operation without water injection.

  For the purpose of enabling quick drainage in response to sudden water discharge, a stand-by type vertical shaft pump capable of pre-standby operation is installed in the pump station. An example of the structure of a conventional prior standby vertical shaft pump will be described with reference to FIG. FIG. 6 is a longitudinal cross-sectional view of an example of the structure of a conventional advance standby type vertical shaft pump.

  In FIG. 6, a discharge elbow 33 of a vertical shaft pump 32 is installed and fixed on a pump installation floor 31 of the suction water tank 30, and a pumping pipe 34, a pump casing 35 and a suction pipe 36 are sequentially connected to the lower end of the discharge elbow 33. It is suspended and the suction pipe 36 is submerged under the water surface. A short pipe 37, a discharge valve 38, and a discharge pipe 39 are sequentially connected to the other end of the discharge elbow 33. The drainage is discharged from the discharge pipe 39 to a drainage destination (not shown). A pump flow path is formed by a pipe line extending from the suction pipe 36 to the discharge pipe 39. An impeller 41 is disposed in the pump casing 35 on a pump shaft 40 that passes through the outer wall of the discharge elbow 33 and is disposed at the axial center of the pumping pipe 34 and the pump casing 35. The pump shaft 40 is rotatably supported by bearings 46 and 47 on the downstream side of the impeller 41 in the pump flow path. As the sliding members of these bearings 46 and 47, rubber bearings formed of a rubber material are generally used. Further, a shaft protection pipe 48 and an inner casing 50 connected to the shaft protection pipe 48 are provided so as to cover the pump shaft 40 and the bearings 46 and 47 in the pump flow path, and water is poured into the upper end portion of the shaft protection pipe 48. Lubricating water is supplied by the pump 49, the lubricating water is also supplied into the inner casing 50 through the shaft protection pipe 48, and further drained to the outside through the drain pipe 51 having one end opened in the inner casing 50. Furthermore, an intake hole 52 is formed in the pipe wall of the suction pipe 36 at a level B upstream of the inlet level C of the impeller 41, and one end of the intake pipe 42 is connected to the intake hole 52, and the other end. Is communicated to the outside air through the intake valve 53.

  In such a configuration, a drive device (not shown) connected to the pump shaft 40 is operated at the time of water discharge, the pump operation of the vertical shaft pump 32 is performed, and the water level of the suction water tank 30 gradually decreases from the high water level. Reaches a level A at which the water reaches a certain depth, air is sucked into the suction pipe 36 through the opened intake valve 53, the intake pipe 42, and the intake hole 52. Transition to mixed operation. Further, when the water level is lowered to the level B where the intake holes 52 are formed, the suction pipe 36 is filled with air and the vacuum is broken, and the water upstream of the impeller 41 is completely dropped, and the air-water mixing is performed. Shift from driving to air driving. Here, even if the water in the suction pipe 36 falls, the water in the pump casing 35 and the pumping pipe 34 on the downstream side of the impeller 41 is retained without dropping due to the falling water regulating action by the rotation of the impeller 41. Operation is continued and airlock operation is performed. Also in this air lock operation, the water in the pump casing 35 and the pumping pipe 34 gradually falls, and when the water in the pump casing 35 and the pumping pipe 34 is completely dropped, a complete air operation is performed. When the water level in the suction tank 30 rises again and reaches the inlet level C of the impeller 41, the pumping is resumed and the pumping operation is resumed.

  While the pump shaft 40 is being rotationally driven, the lubricating water supplied into the shaft protection tube 48 and the inner casing 50 even during the air operation in which the water in the pump casing 35 and the pumping pipe 34 has completely dropped. Thus, the bearings 46 and 47 are lubricated, and no troubles such as wear of the bearings 46 and 47 occur.

  In the conventional vertical shaft pump 32 having the structure shown in FIG. 6 as described above, the shaft protection pipe 48 for supplying lubricating water to the bearings 46 and 47 in order to prevent damage to the bearings 46 and 47 during the air operation. In addition, it is necessary to install incidental facilities such as the inner casing 50 and the water injection pump 49. However, if these incidental facilities are in a failure state at the time of sudden water discharge, the operation of the vertical pump 32 becomes impossible, which may cause a very serious problem. Therefore, in order to ensure reliable operation in an emergency, there is no need for auxiliary equipment as much as possible, and the adoption of a stand-by type vertical shaft pump that uses a non-water-filled bearing that can be operated without the need to inject lubricating water from the outside. It is desired. The conventional vertical shaft pump 32 having the structure shown in FIG. 6 can be operated without water injection by using ceramics or the like for the sliding members of the bearings 46 and 47. However, if a non-water-filled bearing using ceramics or the like as a sliding member is used, it is easy to damage the sliding members of the bearings 46 and 47 due to vibration of the pump shaft 40 that occurs during the airlock operation. There's a problem.

  Therefore, in order to reduce vibrations of the pump shaft 40 during the airlock operation and reduce the load applied to the sliding members of the bearings 46 and 47, the pump shaft 40 is extended to the upstream side of the impeller 41, and the impeller 41 A structure in which the pump shaft 40 is supported by a bearing on the upstream side is also proposed. However, in such a structure, the bearing on the upstream side of the impeller 41 is in an air-free state until the water level rises to the position of the bearing again after the water in the suction pipe 36 has completely dropped. Driving continues. For this reason, there is a high probability that the operation time without water injection will be long, and it is easy to cause damage due to temperature rise and wear, and even a bearing using ceramics etc. as a sliding member was not satisfactory. . The bearings 46 and 47 disposed on the downstream side of the impeller 41 are lubricated by the water held in the pump casing 35 and the pumping pipe 34 during the airlock operation, so that the bearings 46 and 47 are disposed on the upstream side of the impeller 41. The operation time without water injection is shorter than that of the installed bearing, and damage due to wear or the like is reduced accordingly.

  The present invention has been made in view of the circumstances of the prior art, and has a bearing that is excellent in wear resistance even when the air operation time without water is long and the load caused by vibration during air lock operation. An object of the present invention is to provide a vertical shaft pump suitable for the preceding standby operation using the obtained bearing.

  The present invention has been made to solve the above-described problems. The vertical shaft pump of the present invention supports the pump shaft with bearings on the upstream side and the downstream side of the impeller in the pump flow path, and aramid fibers. A ring-shaped square knitting packing made of polytetrafluoroethylene-graphite compound fiber, which forms a sliding member of a bearing disposed on the upstream side, and a composite material of polyether ether ketone and carbon fiber, on the downstream side The sliding member of the bearing arrange | positioned in is formed and comprised.

  The pump shaft is supported by bearings on the upstream side and downstream side of the impeller in the pump flow path, and is arranged on the upstream side with a ring-shaped square knitting packing made of aramid fiber and polytetrafluoroethylene-graphite compound fiber. Formed from a polyether ether ketone and carbon fiber composite material and an aramid fiber and a polytetrafluoroethylene-graphite compound fiber disposed in close proximity or close to the upstream side and downstream side of the composite material The sliding member of the bearing disposed on the downstream side may be formed with a ring-shaped square knitting packing.

  Further, the pump shaft is supported by bearings on the upstream side and the downstream side of the impeller in the pump flow path, and a ring-shaped square braided packing made of aramid fiber and polytetrafluoroethylene-graphite compound fiber, the upstream side and the It is also possible to form a sliding member for each bearing disposed on the downstream side.

  2. The vertical shaft pump according to claim 1, wherein the ring-shaped square braided packing is composed of an aramid fiber and a polytetrafluoroethylene-graphite compound fiber excellent in wear resistance, and is disposed upstream of the impeller. The sliding member of the bearing arranged downstream of the impeller is formed with a composite material of polyether ether ketone and carbon fiber with excellent load resistance. The upstream bearing, which is likely to have a long operating time, is less likely to be damaged by temperature rise and wear, and the downstream bearing, which may be subjected to an excessive load due to air lock operation, is less likely to be damaged by the load. Therefore, it is possible to operate without water injection.

  The vertical pump according to claim 2 is a ring-shaped square knitting packing made of an aramid fiber and a polytetrafluoroethylene-graphite compound fiber excellent in wear resistance, and is disposed upstream of the impeller. A composite material of polyether ether ketone and carbon fiber with excellent load resistance and aramid fiber with excellent wear resistance arranged close or close to its upstream and downstream sides And a ring-shaped square knitted packing made of polytetrafluoroethylene-graphite compound fiber formed a sliding member for the bearing disposed downstream from the impeller, so the probability that the operating time without water injection will be longer High-speed upstream bearing is less susceptible to damage due to temperature rise and wear, and the downstream shaft may be overloaded by airlock operation However, even with liquids that are not easily damaged by load and contain a large amount of wear components such as sand and silt, the wear components are made of a highly wear-resistant material that is placed close to or close to the top and bottom sides. Intrusion to the inside is prevented and wear of the material having excellent load resistance is suppressed. Therefore, it is possible to operate with no water for a liquid containing a lot of wear components.

  The vertical shaft pump according to claim 3 is a ring-shaped square knitting packing made of an aramid fiber and a polytetrafluoroethylene-graphite compound fiber excellent in wear resistance, on the upstream side and the downstream side of the impeller. Since the sliding members of the respective bearings are formed, in the vertical shaft pump improved so as to shorten the airlock operation time, the bearing on the downstream side of the impeller is also subjected to an excessive load due to vibration. Since there is little fear, even if a bearing having excellent wear resistance is provided on the downstream side, sufficient operation is possible. And since the sliding member of a bearing is one type, the kind of components required for maintenance management can be decreased.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view of a first embodiment of the structure of a vertical pump according to the present invention. FIG. 2 is a longitudinal sectional view of a bearing disposed on the upstream side of the impeller. FIG. 3 is a longitudinal sectional view of a bearing disposed downstream of the impeller. In FIG. 1, the same or equivalent members as in FIG.

  In the vertical shaft pump 10 of the first embodiment shown in FIG. 1, the main difference from the conventional example shown in FIG. 6 is that the shaft protection pipe 48, the water injection pump 49 and the drain pipe 51 are omitted, and the pump shaft 40 is It extends to the upstream side from the impeller 41 and is rotatably supported by the bearing 1. Therefore, the pump shaft 40 is rotatably supported by the bearing 1 disposed on the upstream side of the impeller 41 and the bearings 2 and 3 disposed on the downstream side of the impeller 41. As shown in FIG. 2, the sliding member 5 disposed in the bearing box 4 of the bearing 1 on the upstream side of the impeller 41 and in sliding contact with the shaft sleeve 6 of the pump shaft 40 is composed of an aramid fiber and polytetrafluoroethylene. -It is formed of a ring-shaped square knitting packing made of graphite compound fibers and is fitted in four rows. In addition, the lower portion of the bearing box 4 is closed by the lid 7 so that water is accumulated in the bearing box 4. Although it is desirable to provide the lid 7 as in the first embodiment, the lid 7 is not necessarily provided. Further, as shown in FIG. 3, the sliding member 8 disposed on the bearings 2 and 3 on the downstream side of the impeller 41 and in sliding contact with the shaft sleeve 9 of the pump shaft 40 is made of polyether ether ketone which is a thermoplastic resin. It is formed of a composite material made of carbon fiber.

  With the vertical shaft pump 10 configured as described above, a drive device (not shown) connected to the pump shaft 40 is operated at the time of water discharge to perform a pumping operation, the water level of the suction tank 30 gradually decreases from the high water level, and the water level is reduced. When the level A reaches a certain water depth, air is sucked into the suction pipe 36 through the opened intake valve 53, the intake pipe 42, and the intake hole 52. Transition to driving. Further, when the water level is lowered to the level B where the intake holes 52 are formed, the suction pipe 36 is filled with air and the vacuum is broken, and the water upstream of the impeller 41 is completely dropped, and the air-water mixing is performed. Shift from driving to air driving. Then, the water lock operation in which the water in the pump casing 35 and the pumping pipe 34 is held by the falling water regulating action by the rotation of the impeller 41 is performed. Furthermore, when the water in the pump casing 35 and the pumping pipe 34 is gradually dropped, and the water in the pump casing 35 and the pumping pipe 34 is completely dropped, a complete air operation is performed. Then, when the water level in the suction water tank 30 rises again and reaches the inlet level C of the impeller 41, the pumping is resumed and the pumping operation is resumed.

  In such a preliminary standby operation, while the pumping operation is being performed, any of the bearings 1, 2, and 3 is lubricated by running water in the pump flow path. During the airlock operation, the bearing 1 is in a non-water-injected state that is not lubricated by running water, but the bearings 2 and 3 are lubricated by running water held in the pump casing 35 and the pumping pipe 34. Therefore, the bearing 1 disposed on the upstream side of the impeller 41 is likely to have a longer operation time in the non-water-filled state than the bearings 2 and 3 disposed on the downstream side. Further, in the air lock operation, there is a high possibility that an excessive load is applied to the bearings 2 and 3 due to vibration that is likely to occur in the pump shaft 40. Furthermore, when the water in the pump casing 35 and the pumping pipe 34 is completely dropped and the air operation is complete, all of the bearings 1, 2, and 3 are in a non-poured state where they are not lubricated by running water.

  The inventors have conducted many experiments in order to find a material as the sliding members 5, 8, 8 suitable for the use state of the bearings 1, 2, 3. As a result, first, the sliding member 5 of the bearing 1 which is disposed upstream of the impeller 41 and has a high probability of being in the air-operated state without water injection has a high probability of abnormal increase in bearing temperature and abnormal wear due to frictional heat. The present inventors have found a ring-shaped square knitted packing made of aramid fiber and polytetrafluoroethylene-graphite compound fiber as a material that can sufficiently withstand. As an example, an experiment was conducted using a trade name “Alohem 2” marketed by Merkel. The experiment was conducted for 9 hours in a pattern in which the air operation was performed for 1 hour, the pumping operation was then performed for 20 minutes, the air lock operation was further performed for 8 minutes, and the operation was shifted to the air operation again. As a result, it was confirmed that there was no abnormal increase in bearing temperature and abnormal wear damage, and that the bearing had sufficient capacity. In addition, the inventors use, as the sliding member 5, a trade name “Alohem S” marketed by Merkel, which is a ring-shaped square knitting packing made of the same material aramid fiber and polytetrafluoroethylene-graphite compound fiber. Even an experiment was conducted. Similar to “Alohem 2”, sufficient results were obtained. Therefore, it is concluded that a ring-shaped square knitted packing made of aramid fiber and polytetrafluoroethylene-graphite compound fiber can be used as the sliding member 5 of the bearing 1 disposed on the upstream side of the impeller 42. Obtained. Further, as the sliding members 8 and 8 of the bearings 2 and 3 which are disposed on the downstream side of the impeller 42 and are highly likely to be subjected to an excessive load load due to the air lock operation, thermoplasticity as a material having excellent load resistance. The present inventors have found a composite material composed of a polyetheretherketone resin and carbon fiber. As an example, an experiment was conducted using a trade name “WR-525” marketed by Green, Tweed and Company Japan Co., Ltd. In the experiment, the pump shaft 40 having a diameter of 65 mm was rotated at 1500 / min and a load with a surface pressure of 1 MPa was applied to the bearing, and an operation experiment for 50 hours in clean water was performed. As a result, it was confirmed that no abnormality occurred on the sliding contact surface of the sliding member 8 and that the sliding member 8 had a sufficient capability against vibrations in the air lock operation.

  Based on the above experimental results, the sliding member 5 of the bearing 1 is formed of a ring-shaped square knitted packing made of aramid fiber and polytetrafluoroethylene-graphite compound fiber, and the sliding members 8 and 8 of the bearings 2 and 3 are As a result of experiments conducted by the inventors, the actual machine was manufactured by using a composite material composed of polyether ether ketone, which is a thermoplastic resin, and carbon fiber. The performance as the vertical pump 10 for water injection could be confirmed.

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a longitudinal sectional view of a bearing of a second embodiment disposed downstream from the impeller in the vertical shaft pump of the present invention. In FIG. 4, the bearing 12 is formed of a composite material (for example, trade name “WR-525”) in which the sliding member 11 is made of polyetheretherketone and carbon fiber, and closely contacts the upstream side and the downstream side of the bearing 12. The bearings 14 and 15 are arranged, and the sliding members 13 and 13 of the bearings 14 and 15 are ring-shaped square knitted packings (for example, trade name “,” as an example, made of aramid fiber and polytetrafluoroethylene-graphite compound fiber. Alohem S "), and the bearings 12, 14, and 15 form an integral bearing. Such a composite bearing structure is suitable for non-poured water operation with respect to a liquid containing a large amount of wear components such as sand and silt.

  The inventors have formed the sliding members 8 and 8 of the bearings 2 and 3 disposed on the downstream side of the impeller 41 in the first embodiment with a composite material made of polyetheretherketone and carbon fiber. On the other hand, when a durability test was performed using a slurry liquid in which silica sand having a particle diameter of 0.2 mm or less as an abrasion component was added to fresh water and adjusted to a solid concentration of 2000 ppm, the sliding members 8 and 8 were operated for 65 hours. Was worn about 465 μm. The inventors considered that such wear was due to the wear component entering the sliding contact surfaces of the sliding members 8 and 8 formed of a composite material composed of polyetheretherketone and carbon fiber. Therefore, as shown in FIG. 4, the inventors have made a sliding formed of a composite material composed of polyetheretherketone and carbon fiber so that the wear component does not enter the sliding contact surfaces of the sliding members 8 and 8. Bearings 14 and 15 having sliding members 13 and 13 formed of ring-shaped square braid packings made of polytetrafluoroethylene-graphite compound fibers are in close contact with the upstream side and the downstream side of bearing 12 having member 11 respectively. The structure to arrange was devised. The sliding members 13 and 13 of the bearings 14 and 15 prevent the wear component from entering the sliding contact surface of the sliding member 11 of the bearing 12. When a durability experiment was conducted on the bearing having such a composite structure in the same manner as the above experiment, the sliding member 11 formed of a composite material composed of polyetheretherketone and carbon fiber was slightly found even after 500 hours of operation. The amount of wear was only 230 μm.

  Based on the results of the durability test with the slurry liquid described above, as a bearing disposed on the downstream side of the impeller 41, the sliding member 11 is a bearing 12 formed of a composite material composed of polyetheretherketone and carbon fiber, The sliding members 13, 13 are in close contact with the upstream side and the downstream side of the bearing 12 and are integrally formed by bearings 14, 15 formed of ring-shaped square knitted packing made of aramid fiber and polytetrafluoroethylene-graphite compound fiber. By constructing a composite bearing, it is possible to perform a water-free operation with respect to a liquid containing a large amount of wear components such as sand and silt. In the structure shown in FIG. 4, the bearings 14 and 15 are disposed in close contact with the upper and lower sides of the bearing 12, but the sliding formed of a composite material composed of polyetheretherketone and carbon fiber. A member 11 and a sliding member 13 formed of a ring-shaped square knitting packing made of aramid fiber and polytetrafluoroethylene-graphite compound fiber in close proximity or close to the upstream side and downstream side of the sliding member 11. , 13 may be used, and the bearing box in which the sliding members 11, 13, 13 are disposed may be integrated. The sliding members 13, 13 provided on the upper and lower sides respectively prevent wear components from entering the sliding contact surface of the central sliding member 11. The sliding members 13, 13 Of course, the structure is such that the wear component does not enter the sliding contact surface of the sliding member 11 directly from the gap between the sliding members 13, 13 and the sliding member 11 without passing through the contact surface.

  Furthermore, a third embodiment of the present invention will be described with reference to FIG. FIG. 5 is a longitudinal sectional view of a bearing according to a third embodiment disposed downstream of the impeller in the vertical shaft pump of the present invention. In FIG. 5, the bearing 16 has a sliding member 17 formed of a ring-shaped square knitted packing made of aramid fibers and polytetrafluoroethylene-graphite compound fibers (for example, trade names “Alohem 2” or “Alohem S”). Composed. Therefore, on the upstream side and the downstream side of the impeller 41, the pump shaft 40 has bearings 1, 16 made of ring-shaped square knitted packings in which the sliding members 5, 17 are both made of aramid fibers and polytetrafluoroethylene-graphite compound fibers. Will be used. This is because, in a vertical shaft pump that has been structurally improved so that the air lock operation time in the preceding standby operation is shortened, the time for the pump shaft 40 generated by the air lock operation to vibrate is shortened. Since the applied load is reduced, the vertical shaft pump is configured by omitting the use of a composite material made of polyetheretherketone and carbon fiber as a sliding member for the downstream bearing. The sliding members 5 and 17 of the upstream and downstream bearings 1 and 16 are common to the impeller 41, and only one type of the sliding members 5 and 17 is sufficient, and the types of parts required for maintenance management are sufficient. Can be reduced. The structural improvement that shortens the airlock operation time is, for example, by forming a through hole in the pumping pipe 34 or the pump casing 35 in a range that does not affect the pump performance at a position directly above the impeller 41. The water held in the pumping pipe 34 and the pump casing 35 may be dropped through this through hole.

It is a longitudinal cross-sectional view of 1st Example of the structure of the vertical shaft pump of this invention. It is a longitudinal cross-sectional view of the bearing arrange | positioned upstream from an impeller. It is a longitudinal cross-sectional view of the bearing arrange | positioned downstream from an impeller. In the vertical shaft pump of this invention, it is a longitudinal cross-sectional view of the bearing of 2nd Example arrange | positioned downstream from an impeller. In the vertical shaft pump of this invention, it is a longitudinal cross-sectional view of the bearing of 3rd Example arrange | positioned downstream from an impeller. It is a longitudinal cross-sectional view of an example of the structure of the prior | preceding stand-by type vertical shaft pump.

Explanation of symbols

1, 2, 3, 12, 14, 15, 16, 46, 47 Bearing 4 Bearing box 5, 8, 13, 17 Sliding member 6, 9 Shaft sleeve 7 Lid 10, 32 Vertical shaft pump 30 Suction water tank 31 Pump installation floor 33 discharge elbow 34 pumping pipe 35 pump casing 36 suction pipe 37 short pipe 38 discharge valve 39 discharge pipe 40 pump shaft 41 impeller 42 intake pipe 48 shaft protection pipe 49 water injection pump 50 inner casing 51 drain pipe 52 intake hole 53 intake valve

Claims (3)

The pump shaft is supported by bearings on the upstream side and downstream side of the impeller in the pump flow path, and is a ring-shaped square knitted packing made of aramid fiber and polytetrafluoroethylene-graphite compound fiber. A vertical shaft pump comprising: a sliding member for a bearing, and a bearing sliding member disposed downstream of the composite material of polyetheretherketone and carbon fiber. The pump shaft is supported by bearings on the upstream side and downstream side of the impeller in the pump flow path, and is a ring-shaped square knitted packing made of aramid fiber and polytetrafluoroethylene-graphite compound fiber. A ring composed of a polyether ether ketone and carbon fiber composite material and an aramid fiber and a polytetrafluoroethylene-graphite compound fiber disposed in close proximity or close to the upstream side and downstream side thereof A vertical shaft pump characterized in that a sliding member of a bearing disposed on the downstream side is formed with a square knitted packing. The pump shaft is supported by bearings on the upstream side and downstream side of the impeller in the pump flow path, and the upstream side and the downstream side are ring-shaped square knitted packings made of aramid fiber and polytetrafluoroethylene-graphite compound fiber. A vertical shaft pump comprising a sliding member for each of the bearings disposed in the shaft.