JP2009162075A - Vertical shaft pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vertical shaft pump not requiring hitting-in of a hook on a body of a pump machine and capable of enhancing maintenance property by facilitating disassembling work of the pump. <P>SOLUTION: The vertical shaft pump is provided with a rotation shaft 6; an impeller 10 connected to the rotation shaft 6; an underwater bearing 12 for supporting rotation of the impeller 10; and a pump casing 2 for storing the rotation shaft 6 and the impeller 10. The pump casing 2 is constituted from a plurality of division bodies 1a, 1b, 3, and on the division bodies 1a, 1b, 3, load receiving parts 25A, 25B, 25C for supporting load of the division bodies are provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vertical shaft pump, and more particularly to a vertical shaft pump for pumping liquid such as river water or drainage.

  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 casing 506 that houses an impeller 504 is suspended via a suspension pipe 502. 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. Therefore, the vertical shaft pump is regularly inspected to check the wear status of the bearing portion (outer bearing 510 and submerged bearing 508) and impeller 504, and the corrosion status of the 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.

  Conventionally, as an inspection / maintenance method for a vertical shaft pump, there is a method in which the pump is lifted using an overhead crane. However, this method 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 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.

  Further, when the pump is connected to the speed reducer, it is necessary to remove the speed reducer. When the pump is directly connected to the electric motor, it is necessary to remove the power supply line and the electric motor. If a gas turbine is used as the drive source, the gas turbine must be moved after the exhaust and ventilation ducts are removed. In either case, it takes a considerable period of time to lift the pump. Furthermore, it is necessary to secure a space for temporarily storing the removed speed reducer, electric motor, and gas turbine in the pump station.

  In order to solve such a problem, recently, a method of disassembling the pump in the water tank while the pump is installed has been adopted (for example, see Patent Document 2). However, this method also has the following problems. First, a large temporary facility such as an elevator such as a chain block for suspending the disassembled parts and a scaffold for workers is required, which requires a lot of work time and cost. Moreover, since these facilities are installed in a narrow aquarium, the work space is further narrowed, and there is a problem in work safety.

  Secondly, it is necessary to drive a hook into a housing of the pump station (for example, a water tank wall) and attach an elevator such as a chain block to the housing. In this case, when a hook is driven into the housing, the water tightness of the housing is impaired, water enters the housing, and internal reinforcement is corroded, which may impair the soundness of the housing. In addition, since the weight of the disassembled pump parts acts on the housing, the housing needs to have sufficient strength. However, in general, the pump station housing is not designed with such additional loads in mind, so the elevator may not be attached to the housing.

  Thirdly, when there is no housing such as a wall in the vicinity of the pump, it is necessary to construct an installation base at the bottom of the water tank and use this as a working scaffold. However, the construction of this installation stand requires a considerable period of time, and the entire work time is prolonged.

JP 2001-323898 A JP 2007-285253 A

  The present invention has been made to solve the above-described problems, and eliminates the need for driving a hook into the housing of the pump station, making it easy to disassemble the pump and improving the maintainability. The purpose is to provide.

  In order to achieve the above-described object, an aspect of the present invention includes a rotating shaft, an impeller coupled to the rotating shaft, an underwater bearing that supports rotation of the impeller, the rotating shaft, and the impeller. The pump casing is configured by a plurality of divided bodies, and the divided bodies are provided with a load receiving portion that supports the load of the divided bodies. It is a pump.

In a preferred aspect of the present invention, the load receiving portion has a sufficient strength to support at least one of the divided bodies.
In a preferred aspect of the present invention, the load receiving portion is detachably attached to the divided body.

Another aspect of the present invention includes a rotating shaft, an impeller coupled to the rotating shaft, an underwater bearing that supports the rotation of the impeller, a pump casing that houses the rotating shaft and the impeller, A fixed shaft disposed concentrically with the rotating shaft, and the underwater bearing is provided inside an impeller hub of the impeller, and the radial force of the impeller is generated by the fixed shaft and the underwater bearing. It is a vertical shaft pump characterized by supporting.
In a preferred aspect of the present invention, the underwater bearing is arranged in a space whose upper end is sealed.

  According to the present invention, an elevator such as a chain block can be locked to the load receiving portion, and the divided body can be removed by the elevator. Therefore, it is not necessary to drive a hook into the housing such as the wall of the water tank, the pump can be easily disassembled, and the working time can be shortened. In addition, since it is not necessary to drive a hook into the housing, the watertightness of the housing is not impaired, and the strength of the housing need not be considered.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 2 is a sectional view showing the overall configuration of the vertical shaft pump according to the first embodiment of the present invention.
As shown in FIG. 2, the vertical pump is connected to an impeller casing 1 having a suction bell mouth 1 a and a pump bowl 1 b, a suspension pipe 3 that suspends the impeller casing 1 in a water tank, and an upper end of the suspension pipe 3. A discharge bend tube 4, an impeller 10 accommodated in the impeller casing 1, and a rotating shaft (vertical shaft) 6 to which the impeller 10 is fixed. The suspension pipe 3 extends downward through an insertion hole 24 formed in the pump installation floor 22 above the water tank, and is fixed to the pump installation floor 22 via an installation base 23 provided at the upper end of the suspension pipe 3. . The rotary shaft 6 extends in the vertical direction through the discharge curved pipe 4, the suspension pipe 3, and the impeller casing 1. The impeller casing 1 and the suspension pipe 3 constitute a pump casing 2.

  The suction bell mouth 1a opens downward, and the upper end of the suction bell mouth 1a is fixed to the lower end of the pump bowl 1b. The impeller 10 is fixed to the lower end of the rotating shaft 6, and the impeller 10 and the rotating shaft 6 rotate integrally. A plurality of guide vanes 14 are arranged above the impeller 10 (discharge side). These guide vanes 14 are fixed to the inner peripheral surface of the pump bowl 1b. The rotary shaft 6 is rotatably supported by the outer bearing 11 and the underwater bearings 12 and 15. The underwater bearing 12 is accommodated in the pump bowl 1 b and is located above the impeller 10. The underwater bearing 15 is accommodated in the suspension pipe 3. The support member 7 that supports the underwater bearing 12 is fixed to the inner surface of the bowl bush 13, and the bowl bush 13 is supported by the impeller casing 1 via a guide vane 14. The support member 17 that supports the underwater bearing 15 is fixed to the inner peripheral surface of the suspension pipe 3. The underwater bearings 12 and 15 are so-called sliding bearings that are in sliding contact with the rotary shaft 6. Reference numeral 19 denotes a handhole.

  The rotary shaft 6 protrudes upward from the discharge curved pipe 4 and is connected to a drive source 18. When the impeller 10 is rotated by the drive source 18 via the rotary shaft 6, water (handling liquid) in the water tank is sucked from the suction bell mouth 1 a and passes through the pump bowl 1 b, the suspension pipe 3 and the discharge bent pipe 4. To the discharge pipe (not shown). During the vertical pump operation, the impeller casing 1 that houses the impeller 10 and the underwater bearing 12 is located below the liquid level.

  The suspension tube 3 and the pump bowl 1b are fixed to each other by a fastener (not shown) such as a bolt. The suspension pipe 3 and the pump bowl 1b are separated by removing the fastener. Similarly, the pump bowl 1b and the suction bell mouth 1a are fixed to each other by a fastener (not shown) such as a bolt, and the pump bowl 1b and the suction bell mouth 1a are separated by removing the fastener. It is like that. As described above, the suspension pipe 3, the pump bowl 1b, and the suction bell mouth 1a are configured as separate bodies that can be separated from each other. In addition, the suspension pipe | tube 3 can also be comprised from a some division body.

  The suspension tube 3 is provided with a plurality of semi-annular load receiving portions 25A. These load receiving portions 25 </ b> A are fixed to the outer peripheral surface of the suspension pipe 3, and are arranged at equal intervals along the circumferential direction of the suspension pipe 3. Similarly, the pump bowl 1b and the suction bell mouth 1a are also provided with a plurality of semi-annular load receiving portions 25B and 25C. These load receiving portions 25B and 25C are also fixed to the outer peripheral surfaces of the pump bowl 1b and the suction bell mouth 1a, respectively, and are arranged at equal intervals along the circumferential direction of the pump bowl 1b and the suction bell mouth 1a. An elevator such as a chain block or a wire hoist is engaged with these load receiving portions 25A, 25B, and 25C.

  FIG. 3 is a diagram showing a state during the disassembly work and assembly of the pump. In FIG. 3, an elevator 26 such as a chain block or a wire hoist is locked to the load receiving portions 25 </ b> B and 25 </ b> C, and the suction bell mouth 1 a is suspended from the pump bowl 1 b by the elevator 26. Similarly, the pump bowl 1 b can be suspended from the suspension pipe 3 by the elevator 26. Thus, each of the load receiving portions 25A, 25B, and 25C has sufficient strength to support at least one divided body.

  The weight of the suction bell mouth 1 a acts on the pump installation floor 22 via the pump bowl 1 b and the suspension pipe 3. The force acting on the pump installation floor 22 is substantially constant regardless of whether or not the disassembly work is being performed. Therefore, there is no need to reinforce the pump installation floor 22, and the existing pump installation floor 22 can be used as it is. Further, since it is not necessary to drive a hook into the housing such as the wall of the water tank, the watertightness of the housing is not impaired, and the housing does not need to have high strength.

  In addition, as a load receiving part, it is not restricted to the semi-annular member shown in FIG. 2, A through-hole, a hook, and an annular member may be sufficient. For example, a through hole 25D formed in the lower portion of the suction bell mouth 1a as shown in FIGS. 4A and 4B can be used as the load receiving portion. Moreover, a load receiving part can be comprised from the annular member 25E detachably attached to the flange part as shown in FIG. Further, as shown in FIG. 6, a pedestal 27 is provided on the outer surface of the divided body such as the suspension pipe 3 and the pump bowl 1b, and a load receiving portion 25F having a through hole is attached to the pedestal 27 with a fastener such as a bolt. May be. You may use the load receiving part of each of these aspects for one vertical shaft pump.

  Next, a second embodiment of the present invention will be described. FIG. 7 is a sectional view showing a part of a vertical shaft pump according to the second embodiment of the present invention. Note that the configuration and operation of the present embodiment that are not specifically described are the same as those of the first embodiment described above, and thus redundant description thereof is omitted.

  As shown in FIG. 7, in this embodiment, two shafts of the rotating shaft 6 and the fixed shaft 30 are provided, and the underwater bearing 12 is provided in the impeller hub 10 a. Furthermore, as shown in FIG. 7, according to a preferred aspect of the present embodiment, the load receiving portion for disassembling and assembling the pump casing 2 is connected to the coupling portion (flange portion) between the pump bowl 1b and the suction bell mouth 1a. A ring member 25E that is detachably attached and a through-hole 25D formed in the lower part of the suction bell mouth 1a are employed.

  The impeller 10 is basically composed of an impeller hub 10a connected to the rotating shaft 6 and a plurality of impellers 10b fixed to the outer peripheral surface of the impeller hub 10a. The underwater bearing 12 is an internal space 29 of the impeller hub 10a. Is placed inside. The underwater bearing 12 is substantially at the same position as the impeller 10b in the axial direction (the direction in which the rotating shaft 6 extends). The underwater bearing 12 and the fixed shaft 30 arranged concentrically with the rotating shaft 6 support the radial force of the impeller 10 generated by the operation of the pump. The fixed shaft 30 is supported by a plurality of support members 31 fixed to the inner peripheral surface of the suction bell mouth 1a.

  The inner space 29 of the impeller hub 10a is a space whose upper end is sealed. Therefore, an air pocket is formed in the internal space 29, and the underwater bearing 12 is prevented from being immersed in water. Thereby, the infiltration of the slurry which causes wear of the underwater bearing 12 is prevented, and the life of the underwater bearing 12 can be extended.

By disposing the underwater bearing 12 inside the impeller 10, the force acting on the underwater bearing 12 can be reduced as compared with the first embodiment. This principle will be described with reference to FIGS. 8 (a) and 8 (b). FIG. 8A is a schematic view showing a pump support structure according to the first embodiment, and FIG. 8B is a schematic view showing a support structure of a rotary shaft of the pump according to the second embodiment. In the case of the cantilever support structure as shown in FIG. 8A, the radial force F acting on the impeller 10, the radial force f1 acting on the outer bearing 11, the radial force f2 acting on the underwater bearing 12, the outer bearing 11 and Assuming that the distance L between the impeller 10 and the distance H between the impeller 10 and the underwater bearing 12, the following equation is established from the balance of moments.
L × F = f2 × (L−H) (1)
That is,
f2 = L × F / (L−H) (2)

On the other hand, in the case of the support structure of the present embodiment shown in FIG. 8B, the radial force f1 ′ acting on the outer bearing 11, the radial force f2 ′ acting on the underwater bearing 12, and between the impeller 10 and the underwater bearing 12. If the distance H ′ is, the following equation holds from the balance of moments.
L × F = f2 ′ × (L + H ′) (3)
That is,
f2 ′ = L × F / (L + H ′) (4)
Here, since H′≈0, the following expression is derived from Expression (4).
f2 ′ = F (5)
The following formulas are derived from the above formulas (2) and (5).
f2 ′ / f2 = (L−H) / L <1 (6)
Therefore, f2 ′ <f2. From this, it can be seen that the force acting on the underwater bearing 12 is smaller in the support structure according to the second embodiment than in the support structure according to the first embodiment. As a result, the degree of wear and the replacement frequency of the underwater bearing 12 can be reduced.

  Furthermore, according to the present embodiment, since the underwater bearing 12 receives substantially all of the radial force acting on the impeller 10, the radial force acting on the outer bearing 11 and the underwater bearing 15 is reduced, and the bearings 11 and 15 wear. Can be suppressed. Moreover, the underwater bearing 12 arrange | positioned in the impeller 10 can be replaced | exchanged comparatively easily by removing the suction bell mouth 1a. Therefore, replacement work of worn parts becomes easy, and the maintenance of the pump is improved.

  As shown in FIG. 9, in order to reduce the resistance against water flowing into the suction bell mouth 1 a, the tip of the fixed shaft 30 is formed in a curved shape, and the fixed shaft 30 is an outer peripheral surface that is smoothly connected to the bowl bush 13. It is preferable to have. Moreover, it is preferable that the support member 31 of the fixed shaft 30 has a shape that reduces flowing water resistance, such as a wing shape.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible.

It is a schematic diagram which shows the conventional vertical shaft pump. It is sectional drawing which shows the whole structure of the vertical shaft pump which concerns on the 1st Embodiment of this invention. It is a figure which shows the mode at the time of the decomposition | disassembly operation | work of a pump, and an assembly. FIG. 4A is a partial sectional view of a suction bell mouth showing an example of a load receiving portion, and FIG. 4B is a bottom view of the suction bell mouth shown in FIG. It is a figure which shows the other example of a load receiving part. It is a figure which shows the other example of a load receiving part. It is sectional drawing which shows a part of vertical shaft pump which concerns on the 2nd Embodiment of this invention. FIG. 8A is a schematic view showing a pump support structure according to the first embodiment, and FIG. 8B is a schematic view showing a rotary shaft support structure of the pump according to the second embodiment. It is sectional drawing which shows the modification of the vertical shaft pump which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Impeller casing 1a Suction bell mouth 1b Pump bowl 2 Pump casing 3 Suspension pipe 4 Discharge curved pipe 6 Rotating shaft 7, 17 Support member 10 Impeller 10a Impeller hub 10b Impeller 11 Outer bearing 12, 15 Underwater bearing 13 Bowl bush 14 Guide vane Reference Signs List 18 Drive Source 19 Hand Hole 22 Pump Installation Floor 23 Installation Base 24 Pump Insertion Holes 25A-25E Load Receiving Portion 26 Elevator 27 Base 29 Internal Space 30 Fixed Shaft 31 Support Member

Claims (6)

A rotation axis;
An impeller coupled to the rotating shaft;
An underwater bearing that supports rotation of the impeller;
A pump casing for housing the rotating shaft and the impeller,
The pump casing is composed of a plurality of divided bodies,
The vertical shaft pump, wherein the divided body is provided with a load receiving portion that supports a load of the divided body.   The vertical shaft pump according to claim 1, wherein the load receiving portion has a strength sufficient to support at least one of the divided bodies.   The vertical shaft pump according to claim 1, wherein the load receiving portion is detachably attached to the divided body. A rotation axis;
An impeller coupled to the rotating shaft;
An underwater bearing that supports rotation of the impeller;
A pump casing that houses the rotating shaft and the impeller;
A fixed shaft disposed concentrically with the rotating shaft,
The underwater bearing is provided inside an impeller hub of the impeller,
A vertical shaft pump, wherein the radial force of the impeller is supported by the fixed shaft and the underwater bearing.   The vertical shaft pump according to claim 4, wherein the submersible bearing is disposed in a space whose upper end is sealed. The pump casing is composed of a plurality of divided bodies,
The vertical shaft pump according to claim 4 or 5, wherein the divided body is provided with a load receiving portion that supports a load of the divided body.

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