JP2000130390A - Vertical shaft pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vertical shaft pump device having an underwater bearing, capable of performing lubrication without using any external water injection means at the time of pre-standby running time in a no-water state. SOLUTION: This device is constructed in such a manner that an extension part extending to the lower part of an impeller 5 is provided in the lower end of a main spindle 7, the extension part is supported by an underwater bearing 12, and the underwater bearing 12 is housed in a bearing casing 15 having a space 18 inside, the upper part 15b thereof being opened and the lower part 15a thereof being closed. The underwater bearing 12 is lubricated by liquid in the space 18 even in a no-water state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a vertical axis pump device in which an idle operation is performed, such as a rainwater drainage pump requiring a preliminary waiting operation. A longitudinal axis pump device in which a main shaft driving an impeller incorporated in the part extends through the inside of the water pump and is connected to a shaft of a motor installed at the upper part of the water pump, and the main shaft is supported by a submerged bearing. .

[0002]

2. Description of the Related Art As a submersible bearing of a vertical axis pump, a rubber bearing is known as the one most commonly used in the past. This rubber bearing has good sliding properties in water, but is poor in air, so it must be constantly lubricated with water during operation. However, since the vertical pump is generally not filled with water in the pumping pipe before starting, when using rubber bearings, supply sufficient lubricating water from the outside to the submerged bearing in the pumping pipe before starting. Need to start. Therefore, a pressure water source, a water supply pipe, a water supply amount control facility, and its maintenance are required for this purpose.

[0003] Such an external supply system for bearing lubrication water is provided by:
It can be omitted if a self-lubricating synthetic resin bearing or the like is used for the underwater bearing, so that it has been conventionally put to practical use. This technology is applied only to the underwater bearing inside the pumping tube with a small bearing load, and the underwater bearing near the impeller with a large bearing load is submerged before starting and lubricated with water. Therefore, it is not applied to underwater bearings near the impeller. However, in recent years, in the rainwater drainage pumps and the like in urban areas, the use of an operation method of performing a preliminary waiting operation when heavy rain is expected is increasing so as to be able to immediately respond to a rapid rise in water level. In this case, unlike the case of the conventional non-water injection start, the operation is performed in a state where there is completely no water up to the bowl portion, so that the operating condition is extremely severe for the underwater bearing provided in the bowl portion. Therefore, conventionally, lubricating water was externally supplied as shown in FIG.

In order to better understand the present invention, the prior art will be described first with reference to FIG.

In FIG. 6, a pumping tube generally designated by reference numeral 2 is supported on a mounting floor 10 via a gantry 11, and a bowl portion 1 is attached to a lower end of the pumping tube 2. A lower portion of the bowl portion 10 forms a suction port 3, and a discharge port 4 is formed at an upper end of the water pump 2.

[0006] The upper part of the main shaft 7 extending through the pumping pipe 2 is connected to a motor shaft 9 via a shaft coupling 8, and the middle of the main shaft 7 is rotatable by a submerged bearing 14 attached to the pumping pipe 2. , And the lower part is supported by an underwater bearing 13 fixed to the bowl portion 1.

[0007] An impeller 5 is mounted in the bowl portion 1 at the lower end of the main shaft 7. Further, a diffuser vane 6 for converting the velocity energy of water flowing out of the impeller 5 into pressure energy is provided downstream of the impeller 5 in the bowl portion 1.

[0008] Therefore, with the rotation of the impeller 5, the pumped liquid is sucked through the suction port, is pressurized by the diffuser vanes 6, rises in the pumping pipe 2, and is discharged from the discharge port 4.
During that time, the underwater bearings 13, 14 are lubricated by the liquid.

However, as described above, it is necessary to supply external lubricating water to the underwater bearings 13 and 14 during the standby operation, and therefore, the underwater bearing lubricating water supply pipe 22 and its related equipment are required. Costs and maintenance costs have tended to be high and operating procedures complicated.

[0010]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a vertical axis pump device which can perform a long-term standby operation without water injection even with a normal underwater bearing.

[0011]

According to the present invention, a bowl portion is suspended by a water pump, and a main shaft for driving an impeller incorporated in the bowl portion penetrates through the inside of the water pump.
In a vertical axis pump device connected to a shaft of a prime mover installed at an upper part of a water pump, and the main shaft is supported by a submerged bearing, an extension extending below the impeller is provided at a lower end of the main shaft, and the extension is provided. The part is supported by a submerged bearing, and the submerged bearing is housed in a bearing casing having an open upper part and a closed lower part with a space inside.

According to the present invention, an auxiliary impeller is provided on a main shaft so as to face an upper end surface of the underwater bearing or an underwater bearing casing for holding the underwater bearing. A flow path is provided outside the underwater bearing from the space formed between the underwater bearing and the space formed between the bottom and the bottom.

Further, according to the present invention, a pump is provided with a flow passage leading from the discharge side of a pumping pipe or bowl to the space and a flow passage outside the underwater bearing leading from the space to an upper opening of the bearing casing. A part of the pumping water is configured to pass through the inside of the underwater bearing casing.

According to the present invention, means for forcibly turning the water flowing into the space in the rotation direction of the main shaft is provided near the space.

The impeller is the element having the largest mass among the rotating parts of the pump, and therefore the element that maximizes the load on the underwater bearing at the time of starting. Further, the impeller imposes an irregular fluctuating load on the underwater bearing because the flow state fluctuates irregularly in a transitional state in which the impeller shifts from the preceding waiting operation state to the water supply operation.

According to the present invention, the bearing load of such an impeller is supported by the underwater bearing installed below the impeller, and the underwater bearing can be lubricated by the liquid filled in the space. Thus, since it is provided in the bearing casing, it can sufficiently withstand the load of the impeller even in the anhydrous operation.

Further, since the underwater bearing at the bottom bears the load of the impeller, the underwater bearing at the upper part of the bowl and at the pumping tube is
It only has to function as a shaft anti-sway, and a synthetic resin bearing having self-lubricating properties can be used.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 5, and FIG.
The same components as those described above are denoted by the same reference numerals, and redundant description will be omitted.

In FIG. 1, the underwater bearings 13 and 14 each have a self-lubricating property, for example, made of a synthetic resin, so that the underwater bearings can be operated anhydrously during the preliminary waiting operation. The underwater bearing 13 at the lower portion is provided at an intermediate portion in the height direction of the bowl portion 1 in the conventional example shown in FIG. 6, but is provided at an upper portion of the bowl portion 1 in the example of FIG. And the main shaft 7
Has an extension 4a extending below the impeller, and the extension 4a is supported by another underwater bearing 12.

FIG. 2 is an enlarged view of the vicinity of the underwater bearing 12. In the figure, a rib (single or plural) provided on the suction port 3 and extending inward in the radial direction is provided with a bearing casing 15.
The bearing casing 15 is provided with a bearing shell 12a for supporting the underwater bearing 12. The bottom portion 15a of the bearing casing 15 is closed, and the upper portion 15b is open, and a space 18
have. The space 18 is filled with liquid.

Therefore, if the space 18 in the bearing casing 15 is previously filled with liquid at the time of installation, the lower submerged bearing 12 is lubricated with water even during the preceding standby operation, so that highly reliable operation is possible. . During operation, the pumped liquid can flow into the recess 18.

Since the inside of the pump is high in humidity, the water filled in the bearing casing hardly evaporates and is kept for a long time. In addition, even if a small amount of loss occurs, the pump is automatically replenished each time the pump is operated, so that the pump can be maintained in a state in which the preliminary waiting operation can be performed at any time.

In the embodiment shown in FIG.
2 is different from the embodiment of FIG. 2 in that a flow path 15c is provided outside a submerged bearing 12 from a space 18 formed between the lower end surface of the bearing casing 15 and a bottom 15a of the bearing casing 15 to an upper open portion of the bearing casing 15. ing.

By providing the flow path 15b in this way, the water in the bearing casing 15 is mixed and replaced with a part of fresh pumped water every time the pumping operation is performed. At this time, the auxiliary impeller 17 shakes off particles such as earth and sand in the pumping water and suppresses them from entering the bearing casing 15. Therefore, it is possible to prevent the bearing life from being shortened by particles such as earth and sand.

FIG. 4 shows still another embodiment. In this embodiment, a flow passage 16a from the outer surface of the bowl portion 1 to a space 18 formed between the bottom portion 15a of the bearing casing and the underwater bearing 12 is provided with a rib. 16 are provided inside. An outer end of the flow path 16 a on the outer surface side of the bowl portion 1 is connected to a lower part of the pumping pipe 2 by a pipe 19. Other points are shown in Fig. 3.
This is the same as the embodiment.

In the embodiment of FIG. 4, during the pumping operation of the pump, a part of the pumped water is supplied from the lower part of the pumping pipe to the pipe 19 and the flow path 16.
a, the space 18, the flow path 15c, and the suction side of the impeller 5 sequentially, and the water in the bearing casing 15 is constantly replaced with new pumped water, and particles such as earth and sand are discharged from the flow path 15c. Is not deposited in the bearing casing 15. Therefore, it is possible to prevent the bearing life from being shortened by particles such as earth and sand.

It is obvious that the flow paths 15c and 19 reaching the space 18 can be implemented in various modes.

In another embodiment shown in FIG. 5, a liquid chamber 25 is provided at the lower part of the bearing casing 15, and the liquid chamber 25 communicates with the flow path 16a shown in FIG.
And a plurality of nozzles 20 are provided between them, and water in the space 18 is jetted into the space 18 through the nozzles 20. The nozzle 20 is mounted so that the injection direction is obliquely upward in the rotation direction in the tangential direction of the concentric circle of the main shaft. A guide cone 21 is attached to the lower end of the bearing shell 12a inside the space 18.

With this configuration, the water in the space 18 is forcibly swirled by the injection from the nozzle 20. For this reason, particles such as earth and sand are pressed against the inner wall side of the cylindrical portion of the bearing casing 15 by centrifugal force while flowing through the flow path 1.
The air is discharged to the suction side of the impeller 5 through 5c. That is, water having a relatively high particle concentration such as earth and sand flows out from the annular flow passage between the inner wall of the cylindrical portion of the bearing casing 15 and the guide cone 21 through the flow path 15c, but has a low particle concentration such as earth and sand. Part of the water flows out from the upper part of the bearing shell 12a to the suction side of the impeller 5 while bypassing the inside of the guide cone 22 and lubricating the underwater bearing.

Therefore, intrusion of particles such as earth and sand into the sliding portion of the underwater bearing is positively avoided as compared with the embodiment of FIG. 4, and the reliability of the underwater bearing can be further improved.

Although not shown, an impeller may be provided at the end of the main shaft 7 in place of the nozzle 20 to positively discharge soil and the like from the flow path 15c.

[0032]

As described above, according to the present invention, the following excellent effects can be obtained. (1) The upper part of the lower underwater bearing near the impeller is opened,
Since it is disposed in the bearing casing having a closed bottom at the lower part, the preceding waiting operation is possible without supplying lubricating water from the outside.

(2) Since the lower underwater bearing close to the impeller is provided, the load of the underwater bearing in the bowl portion and the pumping pipe can be reduced, and a resin pump can be used for those bearings even in a large-sized pump. Can be

(3) By providing means for actively discharging earth and sand in the space, the life of the lower underwater bearing can be extended.

(4) By providing an auxiliary impeller facing the upper surface of the lower submerged bearing or the lower submerged bearing casing, it is possible to prevent particles such as earth and sand from entering the lower submerged bearing portion, thereby preventing a reduction in bearing life. it can.

(5) Water, which flows into the space below the lower underwater bearing, is swirled by, for example, flowing from a nozzle which jets in a tangential direction of a rotating concentric circle, so that particles such as earth and sand are removed outside the lower underwater bearing. Since the water is discharged from the flow path and the lower bearing is supplied with water having a low particle concentration, it is possible to prevent the bearing life from being shortened due to earth and sand.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a vertical axis pump device showing an embodiment of the present invention.

FIG. 2 is an enlarged view of a lower portion of the bowl portion of FIG. 1;

FIG. 3 is a longitudinal sectional view of a lower portion of a bowl portion of a longitudinal axis pump device according to another embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a bowl portion of a vertical axis pump device showing another embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of a lower bearing portion of a longitudinal axis pump device showing still another embodiment of the present invention.

FIG. 6 is a longitudinal sectional view showing an example of a structure of a conventional vertical axis pump device for a preliminary waiting period operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Bowl part 2 ... Pumping pipe 3 ... Suction port 4 ... Discharge port 5 ... Impeller 6 ... Diffuser vane 7 ... Main shaft 8 ... Shaft coupling 9.・ ・ Motor shaft 10 ・ ・ ・ Installation floor 11 ・ ・ ・ Mounting stand 12 ・ ・ ・ Lower underwater bearing 12a ・ ・ ・ Lower underwater bearing shell 13 ・ ・ ・ Bowl part upper underwater bearing 14 ・ ・ ・ Pumping tube part underwater bearing 15 ・..Bearing casing 15a ・ ・ ・ Bearing casing bottom 15c ・ ・ ・ Lower underwater bearing outer passage 16 ・ ・ ・ Rib 16a ・ ・ ・ Rib inside passage 17 ・ ・ ・ Auxiliary impeller 18 ・ ・ ・ Space 19 ・ ・ ・ Piping 20 ... nozzle 21 ... guide cone 22 ... underwater bearing lubrication water supply pipe

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toru Takikawa 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside Ebara Works Co., Ltd. (72) Inventor Tadashi Osamu 11-1 Haneda Asahi-cho, Ota-ku, Tokyo F term in EBARA CORPORATION (reference) 3H022 AA03 BA01 BA06 CA17 CA47 CA54 DA13 DA16 3J012 AB12 BB01 FB01 GB10 HB04

Claims (4)

[Claims] 1. A bowl part is suspended by a pumping pipe, and a main shaft for driving an impeller incorporated in the bowl part penetrates through the inside of the pumping pipe and is connected to a shaft of a motor installed on an upper part of the pumping pipe. An extension extending below the impeller at the lower end of the spindle, the extension being supported by an underwater bearing; and A vertical axis pump device characterized in that it is housed in a bearing casing having an upper part opened and a lower part closed and having a space inside. 2. An auxiliary impeller is provided on a main shaft so as to face an upper end surface of the underwater bearing or an underwater bearing casing holding the underwater bearing, and between the lower end surface of the underwater bearing and a bottom of the bearing casing. 2. A flow passage communicating from the space to the upper opening to the outside of the underwater bearing.
The vertical axis pump device as described. 3. A flow path leading from the discharge side of a water pumping pipe or bowl to the space and a flow path leading from the space to the upper opening of the bearing casing outside the underwater bearing are provided. The vertical axis pump device according to claim 1, wherein the vertical axis pump device is configured to penetrate the inside of the underwater bearing casing. 4. A vertical axis pump device according to claim 3, wherein means for forcibly turning water flowing into said space in a rotation direction of a main shaft is provided near said space.