JP2012137074A - Vertical shaft pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vertical shaft pump which can easily exchange an intermediate bearing in a state that the pump is installed without being pulled up.SOLUTION: The vertical shaft pump comprises: a blade wheel 10; a guide casing 1 into which the blade wheel 10 is accommodated; a hang-down pipe 3 which hangs down the guide casing 1; a discharge bent pipe 4 connected to the upper end of the hang-down pipe 3; a rotating shaft 6 which extends by passing through the discharge bent pipe 4 and the hang-down pipe 3; an outer bearing 11 arranged in the upper part of the discharge bent pipe 4; a submerged bearing 12 arranged in the lower part of the blade wheel 10; the intermediate bearing 31 arranged between the outer bearing 11 and the submerged bearing 12; and a bearing casing 35 in which the intermediate bearing 31 is accommodated, and which has an open upper end. The intermediate bearing 31 is constituted of a plurality of divided bodies which are dividable along the axial direction of the rotating shaft 6.

Description

  The present invention relates to a vertical pump that pumps liquid such as river water and drainage, and more particularly to a vertical pump that can improve the durability and maintenance of a bearing that supports a rotating shaft and can easily replace the bearing.

  FIG. 1 is a schematic view showing a conventional vertical shaft pump. As shown in FIG. 1, generally, a vertical shaft pump is installed on a pump installation floor 500 at the upper part of a water tank, and a guide casing 506 that houses an impeller 504 is suspended via a suspension pipe 502. The impeller 504 is fixed to a rotating shaft 509, and the rotating shaft 509 is rotatably supported by an outer bearing 510 and an underwater bearing 508.

  Such a vertical shaft pump is operated in a state where the impeller 504 and the underwater bearing 508 are immersed in water, and wear and corrosion of these members gradually occur with the passage of time of use. For this reason, the vertical shaft pump is regularly inspected to check the wear of the bearing portion (outer bearing 510 and submerged bearing 508) and impeller 504, and the corrosion of the guide casing 506, and repair or replace as necessary. It is necessary to do. Among them, damage and wear of the underwater bearing 508 cause abnormal vibrations of the pump, and eventually cause a pump failure (cannot be operated). For this reason, the inspection of the underwater bearing 508 is one of the important inspection items.

  There are two methods for checking and servicing the vertical shaft pump: 1) a method in which the pump is installed, and 2) a method in which the pump is lifted. Since the inspection method 1) does not require the pump to be pulled up, the cost is low and the inspection and maintenance period can be shortened. However, for example, the submerged bearing 508 of the vertical shaft is normally submerged in water, so that it is difficult to appropriately measure or detect the wear state of the submerged bearing 508 by the above method 1), and the underwater bearing 508 is replaced. I can't do that either. Even when the water in the water tank is drained and dried, the underwater bearing 508 is located above the impeller 504, so that the underwater bearing 508 cannot be inspected, maintained, or replaced. That is, even if the water in the water tank is drained and the bearing portion is exposed to the atmosphere, satisfactory inspection cannot be performed due to the problem of the installation position of the bearing.

  Therefore, a method has been proposed in which vibrations of the outer bearing 510 and the pump base 514 that can be measured on the ground are measured and the state of the underwater bearing 508 is indirectly estimated (see Patent Documents 1 and 2). However, in this method, since measurement is not performed near the underwater bearing 508 serving as a vibration source, it is difficult to measure abnormal vibration due to wear of the underwater bearing due to various damping effects up to the measurement point. The damage and wear status cannot be judged.

  On the other hand, according to the above method 2), the wear state of the underwater bearing 508 can be appropriately measured or detected, and the underwater bearing 508 can be replaced. For this reason, in order to confirm the wear of the submerged bearing 508 of the vertical shaft pump, the method 2) has been conventionally performed.

  However, the method 2) is expensive and requires a long time for inspection and maintenance. For example, when a vertical shaft pump is lifted using an overhead crane, a mechanical engineer, an operator, a crane operator, and the like who are inspectors are required, and considerable work costs are required for the lifting. Also, lifting and reassembling a heavy pump can be a dangerous operation.

  In addition, the lifting and inspection work requires inspection and maintenance after the lifting, and then undergoes steps of re-installation, centering, and trial operation, and requires a considerable number of days. In addition, depending on the machine, it is necessary to keep the required amount of drainage at all times even during inspections and maintenance, but the pump being inspected cannot be operated during the inspection period. It is necessary to secure drainage capacity by installing it.

  Thus, as shown in Patent Document 3, a vertical pump having a structure in which a rotating shaft is supported by two bearings, an underwater bearing disposed below an impeller and an outer bearing above a pump installation floor, has been proposed. According to this structure, since the underwater bearing is located below the impeller, the wear state of the underwater bearing can be visually inspected from the suction port, and the underwater bearing can be easily replaced.

  However, when the rotating shaft becomes longer (that is, when the distance between the outer bearing and the submerged bearing becomes longer), the critical speed of the rotating shaft decreases and approaches the rotational speed of the pump. When the critical speed of the rotating shaft becomes close to the rotational speed of the pump, abnormal vibration such as resonance occurs. Therefore, it is necessary to arrange an intermediate bearing between the outer bearing and the underwater bearing. However, since the intermediate bearing is located above the impeller and installed in the casing, it was necessary to pull up the pump in order to replace the intermediate bearing.

Japanese Patent No. 3567140 JP 2004-218578 A Japanese Patent No. 4456579

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide a vertical shaft pump in which an intermediate bearing can be easily replaced while the pump is installed without pulling up the pump. To do.

  In order to achieve the above-described object, one aspect of the present invention includes an impeller, a guide casing in which the impeller is accommodated and a guide vane disposed therein, and a suspension that suspends the guide casing in a water tank. A pipe, a discharge curved pipe connected to the upper end of the suspension pipe, a rotary shaft extending through the discharge curved pipe and the suspension pipe, to which the impeller is fixed, and an upper part of the discharge curved pipe An outer bearing disposed, an underwater bearing disposed below the impeller, an intermediate bearing disposed between the outer bearing and the underwater bearing, and an upper end portion in which the intermediate bearing is accommodated and opened. The intermediate shaft is composed of a plurality of divided bodies that can be divided along the axial direction of the rotary shaft.

In a preferred aspect of the present invention, the shaft support surface of the underwater bearing and the shaft support surface of the intermediate bearing are made of materials having different wear resistance.
In a preferred aspect of the present invention, the intermediate bearing is disposed in the vicinity of the upper end of the suspension pipe.
In a preferred aspect of the present invention, the intermediate bearing is disposed in the discharge curved pipe.

In a preferred aspect of the present invention, a gap is formed between the outer peripheral surface of the intermediate bearing and the inner peripheral surface of the bearing casing.
In a preferred aspect of the present invention, a fitting hole into which a lower portion of the intermediate bearing is fitted is formed at the bottom of the bearing casing, and the fitting hole is located concentrically with the rotating shaft. It is characterized by.
In a preferred aspect of the present invention, a highly viscous fluid is sealed in the gap.

A preferred aspect of the present invention further includes a universal shaft coupling that connects the rotating shaft and a driving shaft for driving the rotating shaft, and the universal shaft coupling transmits torque of the driving shaft to the rotating shaft. However, the outer bearing is configured to be able to expand and contract in the axial direction, and the outer bearing is configured to receive a radial load and a thrust load of the rotating shaft.
In a preferred aspect of the present invention, the discharge curved pipe is separable from the suspension pipe.
The preferable aspect of this invention is further equipped with the loose flange type pipe joint removably attached to the discharge side edge part of the said discharge curved pipe.

In a preferred aspect of the present invention, a discharge pipe connected to the discharge curved pipe is further provided, a manhole is formed in the discharge pipe, and the manhole is covered with a removable cover. .
In a preferred aspect of the present invention, a manhole is formed in the suspension pipe, and the manhole is covered with a detachable lid.

  According to the present invention, the intermediate bearing can be removed from the rotating shaft by sliding the intermediate bearing upward along the rotating shaft, taking out the intermediate bearing from the bearing casing, and further dividing the intermediate bearing vertically along the rotating shaft. . Therefore, it is possible to replace the intermediate bearing without lifting the vertical shaft pump from the water tank. Further, by selecting a bearing material corresponding to the bearing load, it is possible to provide a vertical shaft pump having excellent durability.

It is a schematic diagram which shows the conventional vertical shaft pump. It is a schematic diagram which shows the vertical shaft pump in one Embodiment of this invention. It is a longitudinal cross-sectional view of an intermediate bearing and a bearing casing. It is a horizontal sectional view of an intermediate bearing and a bearing casing. It is a top view of an intermediate bearing. It is the figure seen from the AA line of FIG. It is a figure which shows a mode that an intermediate bearing is taken out from a bearing casing. It is a figure which shows the result of having measured the abrasion of the intermediate bearing and the underwater bearing. It is a horizontal sectional view showing an example in which a key that engages with an intermediate bearing and a bearing casing is arranged. FIG. 10A is a cross-sectional view showing a bearing casing having a fitting hole into which the intermediate bearing is fitted, and FIG. 10B is a cross-sectional view showing a modification in which a step portion is formed at the bottom of the bearing casing. FIG. It is sectional drawing which shows the example by which the seal part was arrange | positioned between the intermediate bearing and the bearing casing. It is sectional drawing which shows the example by which the highly viscous fluid was enclosed with the clearance gap between an intermediate bearing and a bearing casing. It is sectional drawing which shows the further another example of an intermediate bearing and a bearing casing. It is sectional drawing which shows a loose flange type pipe joint. It is a figure which shows a mode that the loose flange type pipe joint was removed. It is a figure which shows a mode that the operator is replacing the intermediate bearing inside a vertical shaft pump. It is a top view which shows the example which inserted the stick | rod in the handhole for replacement | exchange of an intermediate bearing. It is a figure which shows the example which has arrange | positioned the intermediate bearing and the bearing casing in the discharge curved pipe. It is a figure which shows the example which provided the manhole in discharge piping. It is a figure which shows the example which provided the manhole in the suspension pipe. It is a figure which shows the example which removes a discharge curved pipe and replaces | exchanges an intermediate bearing. It is a figure which shows the example which replaces | exchanges an intermediate bearing in the state which lifted the discharge curved pipe with the jack.

  Hereinafter, embodiments of a vertical shaft pump according to the present invention will be described in detail with reference to FIGS. 2 to 22. 2 to 22, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 2 is a schematic view showing a vertical shaft pump according to an embodiment of the present invention. As shown in FIG. 2, the vertical pump is connected to a guide casing 1 having a suction bell mouth 1a and a discharge bowl 1b, a suspension pipe 3 for suspending the guide casing 1 in a water tank 5, and an upper end of the suspension pipe 3 The discharge curved pipe 4, the impeller 10 accommodated in the guide casing 1, and the rotating shaft 6 to which the impeller 10 is fixed are provided.

  The suspension pipe 3 extends downward through an insertion hole 24 formed in the pump installation floor 22 at the upper part of the water tank, and is fixed to the pump installation floor 22 via a pump base 23 provided at the upper end of the suspension pipe 3. ing. The rotating shaft (vertical shaft) 6 extends in the vertical direction through the discharge bent tube 4 and the suspension tube 3, and the lower end thereof is located in the guide casing 1. A pump casing 2 is constituted by the guide casing 1 and the suspension pipe 3. The upper floor F above the pump installation floor 22 is an area that can be inspected at all times, and the water tank unit U below the pump installation floor 22 is an area to be submerged. The discharge curved pipe 4 is provided with at least one hand hole 19 for visually confirming the inside of the pump.

  As shown in FIG. 2, the suction bell mouth 1a is opened downward, and the upper end of the suction bell mouth 1a is fixed to the lower end of the discharge bowl 1b. The impeller 10 is fixed to the lower part of the rotating shaft 6, and the impeller 10 and the rotating shaft 6 rotate integrally. The impeller 10 has a plurality of blades, and a plurality of guide vanes 14 are disposed above (the discharge side) the impeller 10. These guide vanes 14 are fixed to the inner peripheral surface of the guide casing 1 and the outer peripheral surface of the bowl bush 13.

  The rotary shaft 6 is rotatably supported by the underwater bearing 12, the intermediate bearing 31, and the outer bearing 11. The underwater bearing 12 is located below the impeller 10 and supports the lower end of the rotating shaft 6. The underwater bearing 12 is supported by a support member 15 fixed to the inner peripheral surface of the suction bell mouth 1a. Note that an underwater bearing is not disposed inside the bowl bush 13. The outer bearing 11 is provided at the upper part of the discharge curved pipe 4 and supports the upper part of the rotating shaft 6. The intermediate bearing 31 is disposed between the outer bearing 11 and the underwater bearing 12. That is, the intermediate bearing 31 is accommodated in the suspension pipe 3 and supports the intermediate portion of the rotating shaft 6. The intermediate bearing 31 is accommodated in the bearing casing 35. The support member 29 that supports the bearing casing 35 is fixed to the inner peripheral surface of the suspension pipe 3. The intermediate bearing 31, the bearing casing 35, and the support member 29 are disposed in the vicinity of the upper end of the suspension pipe 3. This is to facilitate the inspection and replacement of the intermediate bearing 31.

  The underwater bearing 12 and the intermediate bearing 31 are so-called sliding bearings that are in sliding contact with the rotating shaft 6. The outer bearing 11 is configured not only to receive a radial load but also to receive a thrust load. The outer bearing 11 may be a single bearing capable of receiving both a radial load and a thrust load, or a combination of a radial bearing capable of receiving a radial load and a thrust bearing capable of receiving a thrust load. There may be.

  As shown in FIG. 2, the rotating shaft 6 protrudes upward from the discharge curved pipe 4. The upper end of the rotary shaft 6 is connected to the drive shaft 42 of the speed reducer 41 via a universal shaft joint 45. Furthermore, the speed reducer 41 is connected to a drive source 43. As the drive source 43, a diesel engine, a gas turbine, a motor, or the like can be used. Note that the speed reducer 41 may not be used.

  The universal shaft joint 45 is a joint that can expand and contract in the axial direction while transmitting the torque of the drive shaft 42 to the rotating shaft 6. That is, the universal shaft joint 45 can absorb the displacement of the rotating shaft 6 while transmitting torque to the rotating shaft 6. As the universal shaft joint 45, for example, a floating shaft can be used. As described above, the outer bearing 11 can receive not only a radial load but also a thrust load, so that the weight of the rotary shaft 6 and the impeller 10 can be supported. Therefore, a universal shaft joint 45 that can expand and contract in the axial direction can be adopted as a joint that connects the drive shaft 42 that drives the rotary shaft 6 and the rotary shaft 6.

  When the impeller 10 is rotated by the drive source 43 via the rotating shaft 6, water (handling liquid) in the water tank 5 is sucked from the suction bell mouth 1 a, and the discharge bowl 1 b, the suspension pipe 3, and the discharge bent pipe 4 are drawn. It is transferred to the discharge pipe 20 through. During the drainage operation of the vertical shaft pump, the impeller 10 and the underwater bearing 12 are located below the water surface.

  In the conventional vertical shaft pump shown in FIG. 1, since the submersible bearing 508 is accommodated in the bowl bush, it is difficult to replace the submersible bearing 508 with the vertical pump installed. In the present embodiment, since the underwater bearing 12 is disposed below the impeller 10, if the water inside the water tank 5 is removed and an operator enters the lower part of the vertical shaft pump, the underwater bearing 12 is used using a clearance gauge or the like. The amount of wear and the degree of damage can be easily determined, and the underwater bearing 12 can be easily replaced.

  Thus, since the submersible bearing 12 can be inspected and replaced without pulling up the vertical shaft pump, the cost required for lifting the vertical shaft pump can be reduced, and the downtime during inspection and replacement can be greatly increased. It can be shortened. Therefore, the economical efficiency and reliability of the pump station can be improved. Moreover, since the position of the underwater bearing 12 is lower than the conventional position and is located below the impeller 10, the underwater bearing 12 can be surely submerged during the operation of the pump. Therefore, the water film formed between the underwater bearing 12 and the rotating shaft 6 can suppress wear of the underwater bearing 12 and improve the durability of the underwater bearing 12. In addition, it is possible to adopt a cutless bearing that requires water lubrication.

  Next, the intermediate bearing 31 will be described in detail. FIG. 3 is a longitudinal sectional view of the intermediate bearing 31 and the bearing casing 35, and FIG. 4 is a horizontal sectional view of the intermediate bearing 31 and the bearing casing 35. The intermediate bearing 31 is accommodated in the bearing casing 35. The intermediate bearing 31 includes a bearing pad 32 that contacts the rotating shaft 6 and a bearing holder 33 that holds the bearing pad 32. The bearing pad 32 has a cylindrical shape, and its inner peripheral surface constitutes a shaft support surface that supports the rotary shaft 6 rotatably. The bearing pad 32 can be made of, for example, resin, ceramic, or the like. The bearing holder 33 also has a cylindrical shape, and holds the upper surface, the lower surface, and the outer peripheral surface of the bearing pad 32. The bearing holder 33 is made of steel, for example.

  The bearing casing 35 has an open upper end (hereinafter referred to as an open upper end 35a), and the intermediate bearing 31 is inserted into the bearing casing 35 from the open upper end 35a. An upper opening portion 35 a of the bearing casing 35 is covered with an upper cover 36. The upper cover 36 is detachably attached to the bearing casing 35 with bolts 37. In FIG. 3, the bolt 37 is illustrated in a simplified manner. At the bottoms of the upper cover 36 and the bearing casing 35, through holes 36a and 35b through which the rotary shaft 6 passes are formed. A minute gap d of 1 mm to 10 mm is formed between the outer peripheral surface of the intermediate bearing 31 (that is, the outer peripheral surface of the bearing holder 33) and the inner peripheral surface of the bearing casing 35. The intermediate bearing 31 is sandwiched between the lower surface of the upper cover 36 and the bottom portion of the bearing casing 35, thereby fixing the position of the intermediate bearing 31. As described above, the upper cover 36 and the bolt 37 function as a fixing member that fixes the position of the intermediate bearing 31 accommodated in the bearing casing 35.

  FIG. 5 is a top view of the intermediate bearing 31, and FIG. 6 is a view taken along line AA of FIG. The intermediate bearing 31 is configured to be split into two divided bodies 31A and 31B. The split surfaces 31a, 31b, 31c, 31d of the split bodies 31A, 31B extend along the axial direction (longitudinal direction) of the rotary shaft 6, and are intermediate by dividing the intermediate bearing 31 vertically along the axial direction. The bearing 31 can be removed from the rotating shaft 6. Therefore, the intermediate bearing 31 can be removed without disassembling the rotating shaft 6 or without lifting the rotating shaft 6. Similarly, the intermediate bearing 31 can be attached to the rotating shaft 6 by combining the two divided bodies 31 </ b> A and 31 </ b> B on the rotating shaft 6.

  When checking the wear state of the intermediate bearing 31, the operator visually inspects the intermediate bearing 31 from the through hole 36a of the upper cover 36, or removes the upper cover 36 and visually inspects the intermediate bearing 31. When removing the intermediate bearing 31, as shown in FIG. 7, the upper cover 36 is removed, the intermediate bearing 31 is pulled upward from the bearing casing 35, and the intermediate bearing 31 is divided to remove the intermediate bearing 31 from the rotating shaft 6. . When attaching the intermediate bearing 31, the operator assembles the divided parts of the intermediate bearing 31 on the rotary shaft 6, inserts the intermediate bearing 31 into the bearing casing 35, and attaches the upper cover 36 to the bearing casing 35 with bolts 37. By fixing, the intermediate bearing 31 is installed in the bearing casing 35.

  FIG. 8 is a diagram showing the results of measuring the amount of wear of the intermediate bearing 31 and the underwater bearing 12. In the vertical shaft pump shown in FIG. 8, in order to compare the amount of wear of the bearings, the underwater bearing 16 is disposed between the bearings 31 and 12 in addition to the intermediate bearing 31 and the underwater bearing 12 described above. FIG. 8 shows the results of measuring the wear amounts of the intermediate bearing 31, the underwater bearing 16, and the underwater bearing 12 three times. As can be seen from the measurement results shown in FIG. 8, the greater the distance from the outer bearing 11, the greater the amount of bearing wear. Therefore, in consideration of wear resistance, the shaft support surface of the underwater bearing 12 and the shaft support surface of the intermediate bearing 31 are preferably formed from different materials. Here, the shaft support surface is a surface that supports the rotary shaft 6, and the inner peripheral surfaces of the underwater bearing 12 and the intermediate bearing 31 constitute the shaft support surface.

  In the underwater bearing 12 with a large amount of wear (that is, a large load applied to the bearing), the shaft support surface is made of a material having excellent wear resistance such as ceramics, and in the intermediate bearing 31 with a small load applied to the bearing, the wear resistance is increased. It is preferable that the shaft support surface is made of a resin (for example, PEEK) that is more excellent in moldability for division than the property. As described above, by using an appropriate material for each of the bearings 12 and 31 in accordance with the bearing load and the bearing replacement work, a vertical shaft pump having excellent durability and replacement workability can be obtained.

  Since the underwater bearing 12 is provided below the impeller 10 and at the lower end of the rotating shaft 6, the hard material (for example, ceramics) used for the underwater bearing 12 does not need to be divided when the underwater bearing 12 is removed. Therefore, it is not necessary to consider moldability in selecting the material for the underwater bearing 12. In general, when a ceramic bearing is used, if the water is suddenly passed (drained) during the dry operation, the ceramic bearing may crack due to the temperature change. In this embodiment, since the underwater bearing 12 is almost always submerged in water, there is no risk of cracking even if ceramics are used for the underwater bearing 12, and a highly reliable vertical shaft pump can be obtained.

  As shown in FIG. 3, a gap d is formed between the outer peripheral surface of the intermediate bearing 31 and the inner peripheral surface of the bearing casing 35. Therefore, even if the bearing holder 33 and / or the bearing casing 35 of the intermediate bearing 31 are rusted, the intermediate bearing 31 can be easily removed from the bearing casing 35. Thereby, the burden of the bearing replacement | exchange operation | work in a pump can be reduced, an operation | work can be made easy, and also the safety | security of an operation | work can be improved. As shown in FIG. 9, if necessary, a key 38 that engages the outer peripheral surface of the intermediate bearing 31 and the inner peripheral surface of the bearing casing 35 is provided, and the swing of the intermediate bearing 31 in the bearing casing 35 is provided. In addition, the rotation shaft 6 and the intermediate bearing 31 may be prevented from rotating. In the example shown in FIG. 9, two keys 38 are provided corresponding to the two divided bodies of the intermediate bearing 31. The intermediate bearing 31 may be configured to be divided into three or more divided bodies. Although not shown, the upper cover 36 and the bearing holder 33 may be fixed with bolts or the like in order to prevent the rotation shaft 6 and the intermediate bearing 31 from rotating.

  As shown in FIG. 10A, a fitting hole 35 c into which the lower part of the intermediate bearing 31 is fitted may be formed at the bottom of the bearing casing 35. The depth of the fitting hole 35c is preferably 1 mm or more. The fitting hole 35 c is an annular fitting step portion formed on the bottom portion of the bearing casing 35. The intermediate bearing 31 is inserted into the fitting hole 35 c until the lower surface thereof abuts against the bottom of the bearing casing 35. The diameter of the fitting hole 35 c is substantially the same as the outer diameter of the intermediate bearing 31, and the fitting hole 35 c is located concentrically with the rotating shaft 6. Therefore, by inserting the lower part of the intermediate bearing 31 into the fitting hole 35c, the positioning of the intermediate bearing 31, that is, the centering of the intermediate bearing 31 and the rotary shaft 6 is achieved. Further, in order to reduce adhesion due to rust or the like between the intermediate bearing 31 and the bottom of the bearing casing 35, the bottom of the bearing casing 35 may have a stepped portion 35d as shown in FIG.

  As shown in FIG. 11, between the upper cover 36 and the intermediate bearing 31 and between the bottom portion of the bearing casing 35 and the intermediate bearing 31 so that liquid does not enter the gap d between the bearing casing 35 and the intermediate bearing 31. A sealing member 39 such as an O-ring is preferably disposed between the two. Further, in this case, as shown in FIG. 12, a highly viscous fluid may be sealed in the gap d between the bearing casing 35 and the intermediate bearing 31. By sealing such a highly viscous fluid in the gap d, it is possible to more reliably prevent the intermediate bearing 31 and the bearing casing 35 from sticking due to rust or the like. Furthermore, the vibration and displacement of the intermediate bearing 31 can be prevented by the highly viscous fluid. As the highly viscous fluid, for example, grease or lubricating oil can be used.

  FIG. 13 is a cross-sectional view showing still another example of the intermediate bearing 31 and the bearing casing 35. In this example, the upper cover 36 is not provided, and the intermediate bearing 31 is fixed to the bearing casing 35 by a direct bolt 37. More specifically, a flange 33 a is formed on the upper portion of the bearing holder 33 of the intermediate bearing 31, and this flange 33 a is connected to the upper end of the bearing casing 35 by a bolt 37. In this example, no gap is formed between the outer peripheral surface of the intermediate bearing 31 and the inner peripheral surface of the bearing casing 35.

  The outer peripheral surface of the intermediate bearing 31 (that is, the outer peripheral surface of the bearing holder 33) is a tapered surface, and the inner peripheral surface of the bearing casing 35 is also a tapered surface. The tapered surface of the intermediate bearing 31 and the tapered surface of the bearing casing 35 have shapes corresponding to each other. That is, the diameter of the outer peripheral surface of the bearing holder 33 gradually decreases toward the lower end of the bearing holder 33, while the diameter of the inner peripheral surface of the bearing casing 35 gradually increases toward the upper end of the bearing casing 35. It is getting bigger. Therefore, the tapered surface of the intermediate bearing 31 and the tapered surface of the bearing casing 35 are in close contact with each other.

  When the intermediate bearing 31 is inserted into the bearing casing 35 from above, the respective tapered surfaces come into contact with each other, whereby the intermediate bearing 31 is positioned. Further, the tapered surfaces of the intermediate bearing 31 and the bearing casing 35 can reduce the sliding area between the intermediate bearing 31 and the bearing casing 35 when the intermediate bearing 31 is pulled up. Therefore, the intermediate bearing 31 can be easily taken out from the bearing casing 35. In this example, the fixing member that fixes the position of the intermediate bearing 31 accommodated in the bearing casing 35 is constituted by a bolt 37.

  As shown in FIG. 2, the discharge curved pipe 4 and the discharge pipe 20 are connected via a loose flange-type pipe joint 50. The loose flange type pipe joint 50 will be described with reference to FIG. FIG. 14 is a cross-sectional view showing the loose flange type pipe joint 50. As shown in FIG. 14, the loose flange type pipe joint 50 includes a flange pipe 51 having a first flange 51 a and a second flange 51 b, and a loose abutment against the discharge side flange (discharge side end) 4 b of the discharge curved pipe 4. A flange 53, a seal member (for example, an O-ring) 54 that closes a gap between the flange pipe 51 and the loose flange 53, and a seal holding ring 55 that holds the seal member 54 are provided.

  The discharge side flange (discharge side end) 4 b, the loose flange 53, and the seal holding ring 55 of the discharge curved pipe 4 are fixed to each other by bolts 56 and nuts 57 and 58. The bolt 56 is fixed to the first flange 51 a of the flange pipe 51 by nuts 60 and 61. The bolt 56 is a so-called headless bolt. In FIG. 14, only one set of bolts 56 and nuts 57, 58, 60, 61 is shown, but the discharge bent pipe 4 and the loose flange type pipe joint 50 are connected by a plurality of sets of bolts and nuts. ing. The second flange 51b of the flange pipe 51 and the flange 20a of the discharge pipe 20 are fixed to each other with bolts and nuts (not shown).

  The loose flange 53 is loosely fitted to the flange pipe 51 and is movable in the axial direction with respect to the flange pipe 51. Therefore, the overall length of the loose flange-type pipe joint 50 can be adjusted by changing the relative position of the flange pipe 51 and the loose flange 53. The loose flange type pipe joint 50 is not limited to this example, and a loose flange type pipe joint having another structure may be used.

  Next, a method for replacing the intermediate bearing 31 will be described in detail. When the vertical pump is large enough to allow an operator to enter the inside (for example, a diameter of 1000 mm or more), as shown in FIGS. 15 and 16, the loose flange type pipe joint 50 is connected to the discharge pipe 20 and the discharge curve. The worker enters the interior of the vertical pump through the discharge side opening of the discharge curved pipe 4 and separates the intermediate bearing 31 from the pipe 4. Thus, since only the loose flange type pipe joint 50 is removed, the inspection and replacement of the intermediate bearing 31 can be performed, so that the time required for inspection and replacement of the intermediate bearing 31 can be shortened. During the replacement work, as shown in FIG. 16, the support member 29 that supports the bearing casing 35 can be used as a scaffold.

  In order to prevent a worker from falling when the intermediate bearing 31 is replaced, it is preferable to insert a rod 60 into the hand hole 19 and hook a hook of a safety belt on the rod 60 as shown in FIG. In this case, the hand holes 19 are formed on both sides of the discharge curved pipe 4. The diameter of each hand hole 19 is preferably 150 mm or more. In order to facilitate the replacement work, a projector may be installed on the rod 60. Furthermore, it is possible to install a chain block on the rod 60 and to pull up the intermediate bearing 31 from the bearing casing 35 by this chain block, thereby further improving the work efficiency.

  As shown in FIG. 18, the intermediate bearing 31 and the bearing casing 35 may be disposed in the discharge curved pipe 4. In this case, the support member 29 that supports the bearing casing 35 is fixed to the inner peripheral surface of the discharge curved pipe 4. As shown in FIG. 19, a manhole 61 may be provided in the discharge pipe 20, and an operator may enter the interior of the vertical shaft pump through this manhole 61 to replace the intermediate bearing 31. Normally, the manhole 61 is covered with a detachable lid 62, and the lid 62 is removed when the intermediate bearing 31 is replaced. The diameter of the manhole 61 is preferably 600 mm or more. In this case, as shown in FIG. 19, the loose flange-type pipe joint 50 may be omitted. When the pump has a large capacity (diameter of about 2000 mm or more) and the pump hand hole 19 is 600 mm or more, the manhole 61 may be omitted.

  Furthermore, when the intermediate bearing 31 is disposed in the suspension pipe 3, a manhole 61 may be formed in the suspension pipe 3 as shown in FIG. The manhole 61 is located immediately above the intermediate bearing 31, and an operator can enter the suspension pipe 3 from the manhole 61 using the scaffold 65. As in the example shown in FIG. 19, the manhole 61 is normally covered with a removable cover 62, and the cover 62 is removed when the intermediate bearing 31 is replaced.

  When the vertical pump is a small-diameter pump in which an operator cannot enter, the intermediate bearing 31 can be replaced by removing the discharge curved pipe 4 as shown in FIG. The discharge curved pipe 4 has a suction side flange 4 a that can be attached to and detached from the pump base 23. Therefore, the discharge curved pipe 4 can be removed from the vertical shaft pump by disconnecting the discharge curved pipe 4 from the pump base 23, the suspension pipe 3, and the loose flange type pipe joint 50. When removing the discharge curved pipe 4, the universal shaft joint 45 is first separated from the rotary shaft 6 and the drive shaft 42. Since the universal shaft joint 45 can be removed in this way, there is no need to move or remove the speed reducer 41 and the drive source 43.

  As shown in FIG. 22, the discharge curved pipe 4 may be lifted by a jack 63 and the intermediate bearing 31 may be replaced in that state. In this example, since the temporary placement space for the discharge curved pipe 4 is not required, this example is advantageous when the work space is limited. The method using the jack 63 shown in FIG. 22 can also be applied to a large-diameter pump that allows an operator to enter the inside.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and it goes without saying that the present invention may be implemented in various forms within the scope of the technical idea.

DESCRIPTION OF SYMBOLS 1 Guide casing 1a Suction bell mouth 1b Discharge bowl 2 Pump casing 3 Suspension pipe 4 Discharge curved pipe 5 Water tank 6 Rotating shaft 10 Impeller 11 Outer bearing 12 Underwater bearing 13 Bowl bush 14 Guide vane 19 Hand hole 20 Discharge piping 22 Pump installation Floor 23 Installation base 24 Pump insertion hole 31 Intermediate bearing 32 Bearing pad 33 Bearing holder 35 Bearing casing 36 Upper cover 37 Bolt 41 Reducer 42 Drive source 42 Drive shaft 45 Universal shaft joint 50 Loose flange type pipe joint

Claims (12)

Impeller,
A guide casing in which the impeller is housed and a guide vane is disposed;
A suspension pipe for suspending the guide casing in the water tank;
A discharge bend pipe connected to an upper end of the suspension pipe;
A rotating shaft extending through the discharge bend pipe and the suspension pipe and to which the impeller is fixed;
An outer bearing disposed on an upper portion of the discharge curved pipe;
An underwater bearing disposed below the impeller, and
An intermediate bearing disposed between the outer bearing and the underwater bearing;
A bearing casing in which the intermediate bearing is housed and has an open upper end;
The vertical shaft pump, wherein the intermediate bearing is composed of a plurality of divided bodies that can be divided along the axial direction of the rotating shaft.   The vertical shaft pump according to claim 1, wherein the shaft support surface of the underwater bearing and the shaft support surface of the intermediate bearing are made of materials having different wear resistance.   The vertical shaft pump according to claim 1 or 2, wherein the intermediate bearing is disposed in the vicinity of an upper end of the suspension pipe.   The vertical shaft pump according to claim 1 or 2, wherein the intermediate bearing is disposed in the discharge curved pipe.   The vertical shaft pump according to any one of claims 1 to 4, wherein a gap is formed between an outer peripheral surface of the intermediate bearing and an inner peripheral surface of the bearing casing.   6. A fitting hole into which a lower portion of the intermediate bearing is fitted is formed at the bottom of the bearing casing, and the fitting hole is located concentrically with the rotating shaft. Vertical shaft pump described in 1.   The vertical shaft pump according to claim 5, wherein a highly viscous fluid is sealed in the gap. A universal shaft coupling that connects the rotary shaft and a drive shaft for driving the rotary shaft;
The universal shaft joint is configured to extend and contract in the axial direction while transmitting torque of the drive shaft to the rotating shaft,
The vertical shaft pump according to any one of claims 1 to 7, wherein the outer bearing is configured to receive a radial load and a thrust load of the rotating shaft.   The vertical shaft pump according to any one of claims 1 to 8, wherein the discharge curved pipe is separable from the suspension pipe.   The vertical shaft pump according to any one of claims 1 to 9, further comprising a loose flange type pipe joint that is detachably attached to a discharge side end portion of the discharge curved pipe. A discharge pipe connected to the discharge curved pipe;
11. The vertical shaft pump according to claim 1, wherein a manhole is formed in the discharge pipe, and the manhole is covered with a detachable lid.   11. The vertical shaft pump according to claim 1, wherein a manhole is formed in the suspension pipe, and the manhole is covered with a detachable lid.

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