JP5308084B2 - Vertical shaft pump - Google Patents

Description

  The present invention relates to a vertical shaft pump provided with an underwater bearing that supports a rotating shaft.

  FIG. 1 is a schematic view showing a general vertical shaft pump. As shown in FIG. 1, the vertical shaft pump is installed on the pump installation floor 500 in the upper part of the water tank, and a casing 506 that houses the impeller 504 is suspended via the suspension pipe 502. Such a vertical shaft pump is operated in a state in which the underwater bearing 508 is immersed in water, and the underwater bearing 508 is gradually worn as the usage time elapses. Therefore, the vertical shaft pump is periodically inspected to check the wear state of the underwater bearing 508, and the underwater bearing 508 is repaired or replaced as necessary.

  Wear of the underwater bearing 508 causes abnormal vibration of the pump, and eventually causes a pump failure (unusable). For this reason, the inspection of the underwater bearing 508 is one of the important inspection items. Generally, the maintenance interval for underwater bearings is about 10 years. Therefore, once every 10 years, the casing 506 is disassembled to expose the underwater bearing 508, the wear amount of the underwater bearing 508 is measured using a clearance gauge or the like, and whether or not the underwater bearing 508 should be replaced is determined. to decide.

  As a method of disassembling the vertical shaft pump, there is a method of pulling up the pump using an overhead crane. However, this method is expensive and requires a long time for inspection. For example, when an upright shaft pump is lifted by using an overhead crane, a crane operator is also required, so that considerable work costs are required for the lifting. In addition, it can be said that lifting a heavy pump is dangerous work.

  In addition, after inspection and maintenance of the vertical shaft pump, it is necessary to assemble and restore the vertical shaft pump. This assembling work includes steps of centering the drive source and the pump rotating shaft and trial operation of the vertical shaft pump, and requires a considerable number of days. Furthermore, depending on the pump station, it is necessary to keep the necessary amount of water drained even at the time of inspection. During the inspection period, it is necessary to secure a drainage capacity by installing a temporary pump.

  Therefore, as disclosed in Patent Documents 1 to 4 below, a method for detecting the wear of the underwater bearing without pulling up the pump has been proposed. For example, in Patent Document 1, a dummy member is provided adjacent to an underwater bearing, an electric current is passed through a conductive wire embedded therein, and it is detected that the conductive wire is disconnected due to wear of the dummy member. A method for detecting wear of a bearing is disclosed. However, the life of underwater bearings is generally as long as 10 years or more, and the inside of the pump is usually filled with liquid, so that the conductor itself may corrode and break.

  Patent Documents 2 and 3 disclose techniques for estimating the wear amount of a bearing by measuring indirect physical quantities such as air flow rate, pressure, and vibration value. However, these techniques estimate the amount of wear of the bearing by calculation, and are not reliable in determining an accurate bearing replacement time. In this regard, with the method described in Patent Document 1, it is possible to quantitatively grasp the amount of wear of the underwater bearing and accurately determine the replacement time. However, the number of times the wear of the underwater bearing is detected is limited to 1 degree, and if the wear of the underwater bearing is erroneously detected for some reason, the pump is unnecessarily pulled up.

  Patent Document 4 discloses a method of detecting the wear of an underwater bearing adjacent to a conductor by electrically conducting the conductors by contact between the rotating shaft and the conductor. According to this method, when the pump is operated when the underwater bearing is worn, the conductors are electrically connected to each other due to the swing of the pump rotating shaft, so that the wear of the underwater bearing can be detected any number of times. However, since the conducting wire connected to the electrode plate needs to be disposed in water, there is a possibility that the wear of the underwater bearing may not be detected due to the corrosion or breakage of the conducting wire itself.

JP 2006-161790 A JP 2004-218578 A Japanese Patent No. 3567140 JP 2008-75625 A

  The present invention has been made in view of the above-described conventional problems, and can detect the wear of the submerged bearing with high reliability without disassembling the pump casing, and can accurately determine the amount of wear of the submerged bearing. An object of the present invention is to provide a vertical shaft pump having a mechanism that can be known.

In order to achieve the above-described object, one embodiment of the present invention includes an impeller, a rotating shaft connected to the impeller, a pump casing that houses the impeller and the rotating shaft, and the rotating shaft. underwater bearing having a sliding contact surface for rotatably supported, is disposed adjacent to the water bearing, and a dummy bearing having the same or lower hardness than, said water bearing, it is arranged inside the dummy bearing A plurality of wear detection cores that can visually check the degree of wear of the submerged bearing; and a plurality of wear detection cores connected to the plurality of wear detection cores to detach the plurality of wear detection cores from the dummy bearing , A plurality of cables extending through the wall and extending to the outside of the pump casing, and the ends of the plurality of wear detection cores are in the same plane as the sliding contact surface of the underwater bearing. A vertical shaft pump which is characterized.

In a preferred aspect of the present invention, the plurality of wear detection cores have a pattern indicating a degree of wear of the underwater bearing.
In a preferred aspect of the present invention, a color indicating the degree of wear of the underwater bearing is attached to the plurality of wear detection cores.
In a preferred aspect of the present invention, the plurality of wear detection cores are made of a material having a hardness equal to or lower than that of the dummy bearing.
In a preferred aspect of the present invention, the plurality of cables are accommodated in a conduit that communicates the inside and the outside of the pump casing.

  According to the present invention, since the worker can pull up the wear detection core through the cable and directly check the degree of wear of the wear detection core, the highly reliable wear detection and inspection work can be performed. Can do. Further, since the wear amount of the wear detection core is equal to the wear amount of the underwater bearing, the accurate wear amount of the underwater bearing can be known. Furthermore, since an electrical device such as a continuity detector is unnecessary, there is no possibility of erroneous detection of wear due to an electrical malfunction.

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 1a and a pump bowl 1b, a suspension pipe 3 for suspending 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 pump casing 2 includes an impeller casing 1 and a suspension pipe 3.

  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 outer bearing 11 is fixed to the discharge curved pipe 4. 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.

This vertical shaft pump has a mechanism for detecting the amount of wear of the underwater bearings 12 and 15. Since the wear amount detection mechanism for the underwater bearing 12 and the wear amount detection mechanism for the underwater bearing 15 have the same configuration, the wear amount detection mechanism for the underwater bearing 15 will be described below.
FIG. 3 is a vertical sectional view showing the underwater bearing 15, and FIG. 4 is a horizontal sectional view showing the underwater bearing 15. The support member 17 that supports the underwater bearing 15 includes a cylindrical bearing case 17 a that houses the underwater bearing 15, and an arm 17 b that connects the bearing case 17 a to the pump casing 2. The arm 17 b is fixed to the inner surface of the pump casing 2. A conduit 30 that connects the inside and the outside of the pump casing 2 is connected to the support member 17.

  Inside the underwater bearing 15, a plurality of rod-shaped wear detection cores 32 are arranged. These wear detection cores 32 are arranged along the radial direction of the rotary shaft 6, and the tip of each wear detection core 32 is located in the same plane as the inner peripheral surface (sliding contact surface) of the underwater bearing 15. Yes. A cable 35 is connected to the other end of the wear detection core 32. The cable 35 passes through the inside of the conduit 30 through the through hole 36 formed in the bearing case 17 a and extends to the outside of the pump casing 2. More specifically, the end of the cable 35 is located above the pump installation floor 22. The conduit 30 is laid through the inside of the arm 17 b and the wall of the pump casing 2. One end of the conduit 30 is connected to the through hole 36 of the bearing case 17a, and the other end is located above the pump installation floor 22.

  The wear detection core 32 is fixed to the underwater bearing 15 by a resin material or an adhesive, and is detached from the underwater bearing 15 when a strong force is applied. Therefore, by pulling the cable 35, the wear detection core 32 can be removed from the underwater bearing 15 and pulled up above the pump installation floor 22 through the conduit 30.

  Since the wear detection core 32 is arranged in parallel with the underwater bearing 15, when the underwater bearing 15 is worn, the wear detection core 32 is also worn by the same amount. FIG. 5 is an enlarged view showing the worn wear detection core 32. The amount of wear of the wear detection core 32 can be obtained by comparing the length of the wear detection core 32 with the length of the initial wear detection core 32. Therefore, the worker can know how much the underwater bearing 15 is worn by measuring the wear amount of the wear detecting core 32. The wear amount of the wear detection core 32 is not a value estimated from a physical quantity such as electricity or pressure, but is a value that directly indicates the wear amount of the underwater bearing 15, so that the wear amount can be detected with high reliability. . Moreover, since an electrical device such as a continuity detector is unnecessary, there is no risk of malfunction of the electrical device, and the wear amount of the underwater bearing can be known with a simple structure.

  Here, it is preferable to provide a pattern such as a scale indicating the degree of wear on the wear detection core 32. For example, as shown in FIG. 6A, a single wire indicating that the replacement timing of the underwater bearing is approaching and a double line indicating the wear limit value of the underwater bearing are attached to the surface of the wear detection core 32. be able to. A numerical scale indicating the amount of wear may be attached to the surface of the wear detection core 32. Furthermore, as shown in FIG. 6B, a pattern made of a scribing line may be formed on the surface of the wear detection core 32. Instead of the pattern, as shown in FIG. 6C, the wear detection core 32 may be colored with the degree of wear. By applying such a pattern or coloring to the wear detection core 32, the degree of wear of the underwater bearing can be immediately determined without measuring the length of the wear detection core 32 (that is, the amount of wear). improves.

  Further, by examining the degree of wear by pulling up a plurality of wear detection cores 32 one by one at a predetermined operating time interval or at a regular date interval, it is possible to know the tendency of wear of the underwater bearing. The time can be predicted. From such a viewpoint, the number of wear detection cores 32 to be installed is preferably equal to or greater than a value obtained by dividing the expected life (year) of the underwater bearing by the inspection interval (year). For example, as shown in FIG. 7 (a), a plurality of wear detection cores 32 may be arranged over the entire circumference of the rotary shaft 6, or the direction in which the rotary shaft 6 extends as shown in FIG. 7 (b). A plurality of wear detection cores 32 may be arranged along (vertical direction).

  The material constituting the wear detection core 32 is preferably a material having a hardness comparable to or lower than that of the underwater bearing so as not to affect the function of the underwater bearing, and the same material as that of the underwater bearing is used. May be configured. The cable 35 is preferably made of a material having excellent corrosion resistance such as stainless steel. For example, as an example of the cable 35 to be used, a steel wire such as a piano wire or a wire can be given. Also, a resin cable such as an optical cable may be used.

  FIG. 8 is a cross-sectional view showing the arrangement of wear detection cores according to the second embodiment of the present invention. In this embodiment, a dummy bearing 40 is provided adjacent to the underwater bearing 15, and a plurality of wear detection cores 32 are disposed inside the dummy bearing 40. The dummy bearing 40 has a hardness equal to or lower than the hardness of the underwater bearing 15. Preferably, the dummy bearing 40 is made of the same material as the underwater bearing. Other configurations are the same as those of the first embodiment. Also in the present embodiment, the wear amount of the underwater bearing 15 can be obtained from the wear amount of the wear detection core 32.

  FIG. 9 is a cross-sectional view showing a vertical shaft pump in which the lower underwater bearing 12 is disposed below the impeller 10. Also in this example, a plurality of wear detection cores 32 can be provided inside or adjacent to the underwater bearing 12. The vertical shaft pump shown in FIG. 9 is the same as the vertical pump shown in FIG. 2 except that the positions of the underwater bearing 12 and the wear detection core 32 are different.

  The embodiment described above is described for the purpose of enabling the person having ordinary knowledge in the technical field to which the present invention belongs to implement the present invention. Various modifications of the above embodiment can be naturally made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Therefore, the present invention should not be limited to the described embodiments, but should be the widest scope according to the technical idea defined by the claims.

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 vertical sectional view showing an underwater bearing. It is a horizontal sectional view showing an underwater bearing. It is an enlarged view which shows the abrasion detection core worn out. FIG. 6A is a diagram showing an example in which a scale indicating the degree of wear is provided on the wear detection core, and FIG. 6B is a diagram showing an example in which a pattern made of a marking line is attached to the wear detection core. FIG. 6C is a diagram showing an example in which the wear detection core is colored. FIG. 7A is a horizontal sectional view showing an example in which a plurality of wear detection cores are arranged over the entire circumference of the rotating shaft, and FIG. It is a longitudinal cross-sectional view which shows the example which has arrange | positioned the abrasion detection core. It is sectional drawing which shows arrangement | positioning of the wear detection core which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the vertical shaft pump by which the underwater bearing is arrange | positioned below the impeller.

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 Support member 10 Impeller 10a Impeller hub 10b Impeller 11 Outer bearing 12, 15 Underwater bearing 13 Bowl bush 14 Guide vane 18 Drive Source 17 Support member 19 Hand hole 22 Pump installation floor 23 Installation base 24 Pump insertion hole 30 Conduit 32 Wear detection core 35 Cable 36 Through hole 40 Dummy bearing

Claims (5)

Impeller,
A rotating shaft coupled to the impeller;
A pump casing that houses the impeller and the rotating shaft;
An underwater bearing having a sliding contact surface that rotatably supports the rotating shaft;
A dummy bearing disposed adjacent to the underwater bearing and having a hardness equal to or lower than that of the underwater bearing;
Wherein disposed inside the dummy bearing, a plurality of wear detecting core can be confirmed by visual observation the degree of wear of the water bearing,
A plurality of cables connected to the plurality of wear detection cores to detach the plurality of wear detection cores from the dummy bearing, and extending through the wall of the pump casing to the outside of the pump casing;
The vertical shaft pump characterized in that ends of the plurality of wear detection cores are in the same plane as a sliding contact surface of the underwater bearing.   The vertical shaft pump according to claim 1, wherein the plurality of wear detection cores have a pattern indicating a degree of wear of the underwater bearing.   The vertical shaft pump according to claim 1, wherein a color indicating a degree of wear of the underwater bearing is attached to the plurality of wear detection cores. The vertical pump according to any one of claims 1 to 3, wherein the plurality of wear detection cores are made of a material having the same or lower hardness as the dummy bearing. The vertical shaft pump according to any one of claims 1 to 4, wherein the plurality of cables are accommodated in a conduit that communicates the inside and the outside of the pump casing.

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