JPH0544555Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a vertical shaft used in pump intake valves or rainwater pump equipment of drainage pumping stations installed mainly for draining waterways during floods. The present invention relates to pumps, and particularly to vertical shaft pumps that are capable of operating in air, such as advance standby operation.

[Conventional technology] Conventionally, in the pump suction well as described above,
As shown in FIG. 3, a suction bell mouth 104 is connected to impeller casings 102 and 103 containing an impeller 107, and the suction bell mouth 104 is submerged below the water surface WL to suck up water. A pump was used. however,
In a vertical shaft pump like the one shown in Figure 3, when the water level in the suction well falls below a certain level (minimum water level) relative to the pump, it creates a vortex and sucks in air. In order to avoid abnormal vibrations and noise caused by this, conventionally, when the water level in a water suction well or the like falls below the minimum water level, the operation of the pump is usually stopped.

However, with the above-mentioned vertical shaft pump, it is difficult to determine the correct timing to start the pump when the water level rises rapidly. proposed a vertical shaft pump that enables advance standby operation.

The vertical shaft pump shown in FIG. 4 is an example of a vertical shaft pump that enables advance standby operation.
is arranged above the minimum water level LWL mentioned above, and the impeller casings 202, 203
By providing a suction pipe 209 connecting these between the suction bell mouth 204 and the suction bell mouth 204, the suction bell mouth 204 is disposed below the lowest water level LWL and near the impeller inlet level IL.
It is formed by connecting an intake passage 208 equipped with an intake valve 210. Then, when the water level in the water intake well decreases to below the impeller inlet level IL,
By opening the intake valve 210 and sucking air into the suction cylinder 209, a vacuum break is caused and water is not pumped below the lowest water level LWL, thereby supporting the advance standby operation as described above. That's what I do.

On the other hand, recently, sliding bearings made of ceramics with excellent wear resistance have been widely used for the main bearings 211 and 212 that pivotally support the main shaft 201 to which the impeller 207 is attached. .

[Problem to be solved by the invention] However, when air operation such as advance standby operation is started as shown in Fig. 4 above,
During this air operation, the main bearings 211 and 212, which employ sliding bearings as described above, are exposed in the air. However, when using the main bearings 211, 212 as described above, that is, plain bearings, if operation continues for a long time without receiving lubricating water, the main bearings 211, 212 themselves will not have the same heat resistance as ceramics. Even if the main bearings 211 and 212 are made of a superior material, they may be damaged, and even if the main bearings 211 and 212 are not damaged, there is a high possibility that the main shaft 201 side will be damaged.

This invention was devised in view of the above-mentioned circumstances, and the object is to provide a vertical shaft pump that can efficiently supply lubricating water to a sliding bearing that pivotally supports a main shaft.

[Means for Solving the Problems] In order to achieve the above object, the vertical shaft pump according to the present invention is provided with an impeller above the minimum water level unique to the pump, and when the water level falls below the impeller inlet level. , at least before the water level drops below the minimum water level, air can be introduced into the pump from between the impeller inlet level and the minimum water level for air operation, and the main shaft to which the impeller is attached is a sliding bearing. A shaft-supported main body pump, a lubricating water pump whose suction port is installed below the lowest water level of the main body pump, and a lubricating water pump that supplies water sucked by the lubricating water pump to the sliding bearing of the main body pump. It is characterized by being equipped with a water supply pipe that supplies water as water.

[Function] In the vertical shaft pump configured as described above, the suction port of the lubricating water pump is submerged in water even when operating in air, so the lubricating water pump sucks water and sends the water through the water supply pipe. Through this, lubricating water can be supplied to the sliding bearing that pivotally supports the main shaft.

[Example] Hereinafter, an example of the present invention will be described with reference to FIG.

FIG. 1 shows the vertical shaft pump of this embodiment.
The vertical shaft pump shown in FIG. 1 includes a main body pump 1 and a lubricating water pump 4.

The main body pump 1 includes an impeller 20 pivotally supported within a main body casing 10.

The main casing 10 is the pump casing 1
1. Impeller casing 12, pumping pipe 13, discharge elbow 14 and intake passage connecting pipe 15, suction pipe 16
It becomes by concatenating.

Pump casing 11 and impeller casing 12
is the pump casing 11 on the upper or downstream side.
In addition, an impeller casing 12 is disposed below, that is, on the upstream side, and is connected to each other to form a ball-shaped space, in which the impeller 2 is placed.
0 is stored. A lift pipe 13 is connected to the downstream side of the pump casing 11, and a discharge elbow 14 is connected to the downstream side of the pump casing 11.
is connected. Reference numeral 17 denotes a discharge valve installed on the downstream side of the discharge elbow.

The intake passage connecting pipe 15 is located at a position connecting the impeller casing 12 and the suction cylinder 16 on the upstream side of the impeller casing 12;
It is integrally formed with.

The intake passage 1 is provided on the side wall of the intake passage connecting pipe 15.
8 are connected. The connection position of this intake passage 18 is provided above a specific part of the pump corresponding to the lowest water level LWL of this pump. This lowest water level LWL is a water level below which the submerged water level of the suction bell mouth 16a, which will be described later, causes air to be sucked through the opening of the suction bell mouth 16a.

The intake passage 18 is equipped with an intake valve 19 therein. This intake valve 19 is, for example, a first
As shown in the figure, the opening/closing is controlled by an electrical detection signal generated based on the water level detected by the water level detector 5 installed in the pump water suction well, and when the water level starts to drop, the water level increases at the impeller inlet. When the water level reaches the lowest water level LWL below level IL, it opens to allow air to flow into the intake passage connecting pipe 15, and when the water level rises, when the water level reaches the impeller inlet level 11, the valve closes to allow air to flow in. controlled to stop.

The impeller 20 is attached to the lower end of the main shaft 21 that passes upward through the curved portion of the discharge elbow 14, and, as is clear from the above, is arranged above the lowest water level LWL. There is. The main shaft 21 is driven by an electric motor or an internal combustion engine (not shown) disposed above.

The suction cylinder 16 is equipped with a suction bell mouth 16a that opens downward at the lower end, and a pump specific portion S of this pump corresponding to the lowest water level LWL is located in the middle of the suction bell mouth 16a.

The main shaft 21 is supported within the main body casing 10 by sliding bearings 31 and 32.
These slide bearings 31 and 32 each have a sliding surface made of ceramic and are supported on the inner wall of the main body casing 10 via bearing stands 13a and 11a. Further, a shaft sealing mechanism 33 made of a gland packing or the like is provided at the main shaft 12 penetrating portion of the discharge elbow 14 to prevent the sucked water from leaking from the main shaft penetrating portion.

Next, the attached pump 4 will be explained.

This attached pump 4 has an impeller 50 pivotally supported within a casing 40.

The casing 40 is configured by connecting a pumping pipe section 42 to the downstream side (upper side in the figure) of the impeller casing 41 and connecting a suction bell mouth 43 to the upstream side. It is supported on the inner wall of the suction cylinder 16 via a support stand 16b. The suction bell mouth 43 is provided with its open end protruding downward from the open end of the suction bell mouth 16a of the main pump 1. Reference numeral 44 denotes a filter attached to the opening of the suction bell mouth 43, which filters the water sucked up by the attached pump 4.

The impeller 50 is the impeller 20 of the main pump 1
and the main shaft 21 of this impeller 20
The rotary shaft 51 is fixed to the lower end of a rotating shaft 51 that is disposed on the same axis as the rotary shaft 51. The position of this impeller 50 is below the lowest water level LWL of the main pump 1, so that even if the water level reaches this lowest water level LWL, water can be pumped without any problem. Further, a shaft sealing mechanism 61 is attached to a penetrating portion of the rotating shaft 51 into the casing 40 .

A water supply pipe 70 is provided to supply lubricating water sucked by the attached pump 4 and filtered by the filter 44 to the main bearings 31 and 32 of the main pump 1. This water supply pipe 70 is
After being connected to the side wall of the lift pipe 42 of the attached pump 4, it passes through the lift pipe 16 of the main pump 1, extends to the outside of the main pump 1, and is branched into two parts at the outside, each of which is connected to a lift pipe 13. and main bearings 31, 32 passing through the pump casing 11.
Piping is installed to reach the installation part.

Next, the operation of the vertical shaft pump configured as described above will be explained.

In the region A where the submersion depth water level of the vertical shaft pump disposed in the pump pit P is above the water level WL at which the impeller 20 is submerged, normal drainage operation is performed by the pumping action of the impeller 20. .

Even if the water level decreases due to drainage operation and reaches the area B below the water level WL, there is no problem with the drainage action, and if the water level further decreases and reaches the area C below the impeller inlet level IL, the water level is detected. Total 5
An intake valve 19 provided in the intake passage 18 is opened by the detection signal detected by the intake valve 19 . At this time, since the inside of the pump has a negative pressure as the water level continues to fall, air is sucked into the vicinity of the impeller inlet in the intake passage connection pipe 15 via the intake passage 18. By suctioning this air, the suction cylinder 16
The water inside is broken by vacuum and falls, the pump becomes unable to pump water, and the impeller 20 performs upper water retention operation. That is, in the region where the water level is below C shown in the diagram, the upper water retention operation, that is, the air operation is performed and no water is pumped up, so that no air suction vortices or breathing phenomena occur.

When the water level rises from region C to region B, the intake valve 19 provided in the intake passage 18 is closed, and the self-priming effect of the impeller 20 sucks up the remaining air, thereby starting pumping operation.

On the other hand, while the impeller 20 of the main pump 1 is rotating, that is, during operation, this impeller 2
The rotating shaft 51 of the lubricating water pump 4, which is fixed at zero, also rotates. Moreover, since the open end of the suction bell mouth 43 of the lubricating water pump 4 is provided to protrude downward from the open end of the suction bell mouth 16a of the main pump 1, the lubricating water pump 4 The impeller 50 constantly pumps up water and sends lubricating water to the water supply pipe 70. still,
The lubricating water sent into the water supply pipe 70 passes through the filter 44
The lubricating water for sliding bearings is filtered to remove foreign substances that are not suitable for lubricating water for plain bearings. In this way, the lubricating water constantly fed into the water supply pipe 70
It is supplied to main bearings 31 and 32, respectively.

That is, in the vertical shaft pump of the above embodiment, even if the water level falls to the C region and the main pump 1 is operated in the air, the lubricating water pump 4 continues to pump water regardless of this, and the main bearings 31 and 32 Supply lubricating water.

The vertical shaft pump of the embodiment shown in FIG. 1 as described above does not require a special drive source to drive the lubricating water pump 4, and therefore can be realized at low cost. Furthermore, since the lubricating water pump 4 is automatically driven by operating the main body pump 1, control is simple. Furthermore, in the case of a small pump such as the lubricating water pump 4, it is generally driven by an electric motor, but in the above embodiment, if the main body pump 1 is driven by an internal combustion engine. Another advantage is that the lubricating water pump 4 is driven regardless of power outages.

Next, another embodiment of the present invention will be described with reference to FIG.

The structure of the main pump 1 in the vertical shaft pump shown in FIG. 2 is exactly the same as that in the embodiment shown in FIG. 1, so a description of the main pump 1 will be omitted here.

The lubricating water pump 4' in this embodiment is an electric submersible pump, and is installed with the suction port 43' located below the open end of the suction bell mouth 16a of the main pump 1. In addition, the suction port 4
A filter 44' for removing foreign matter is provided at 3'.

The motor casing 4 is located below the suction port 43'.
5' are connected to each other, and an electric motor (not shown) is installed inside. On the other hand, an impeller casing 41' is connected above the suction port 43', and an impeller (not shown) is installed inside. This impeller casing 41' is arranged below the lowest water level LWL of the main casing 1, and therefore the impeller in this impeller casing 41' is always submerged when the water level is above the lowest water level LWL. It has water. As will be described later, this lubricating water pump 4' has a water level detector 5 as well as the intake valve 19.
control based on the detection signal.

Reference numeral 6 denotes a control unit that inputs a detection signal indicating the water level from the water level detector 5, and this control unit 6 inputs a signal that controls the intake valve 19 and the electric motor of the lubricating water pump 4' based on the detection signal. Output.

The water supply pipe 70' is connected to the discharge port of the lubricating water pump 4', and after branching into two, the water supply pipe 70' is connected to the water pump 13 of the main pump 1 and the pump casing 11, respectively.
Piping is provided to penetrate through the main bearings 31 and 32 and reach the main bearings 31 and 32 installation section.

In the vertical shaft pump configured as described above, the intake valve 19 installed in the intake passage 18 is controlled to open and close in the same manner as in the first embodiment described above, by the control signal output from the control section 6. be done.

On the other hand, the control unit 6 determines that the water level is at the impeller inlet level.
If the water level is in region C below IL, the electric motor of the lubricating water pump 4' is driven; if the water level is in region A or B above the impeller inlet level IL, the motor of the lubricating water pump 4' is driven. Outputs a control signal to stop the motor. Therefore, in this embodiment, the lubricating water pump 4' is connected to the intake valve 19.
The lubricating water is supplied to the main bearings 31 and 32 via the water supply pump 70', and is operated only when the main body pump 1 is in an air operation in which water cannot be pumped.

However, in the embodiment shown in FIG. 2, the lubricating water pump 4' may be operated at a time when the water level is equal to or higher than the impeller inlet level IL. ,3
It is sufficient if lubricating water can be supplied to 2.

It should be noted that the present invention is of course not limited to the embodiments described above, and for example, the configuration of the main pump is such that when the water level falls below the impeller inlet level IL of the main pump, Any pump that can be operated in air by introducing air into the pump from between the impeller inlet level and the lowest water level by the means described above may be used. Therefore, as for the main body pump, as shown in Utility Application No. 13336, filed earlier by the applicant, when the water level falls below the impeller inlet level, the suction bell mouth should be raised above the water surface. It may be possible to operate in air by raising the pump and introducing air into the pump.

In addition, the water pumped by the lubricating water pump is
In addition to being used as lubricating water for the main bearing, which is a sliding bearing, it may also be used for other purposes, such as cooling water for the shaft sealing mechanism 33 in FIG.

[Effects of the invention] As is clear from the above explanation, the vertical shaft pump according to the invention can operate regardless of the water level, and can supply lubricating water to the bearing part of the main shaft, which is a sliding bearing, during submerged operation. . Therefore, the vertical shaft pump according to the present invention does not easily damage the bearing part even if it is used for long periods of standby operation, and is suitable for use in recent water intake wells, etc. where the water level fluctuates rapidly. It is extremely easy to use and can be particularly advantageously adopted.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway block diagram of a vertical shaft pump according to an embodiment of the present invention, FIG. 2 is a partially cutaway block diagram of a vertical shaft pump of another embodiment, and FIG. The figure is a side view of a conventional example, and FIG. 4 is a side view of a prior art. 1... Main body pump, 4, 4'... Lubricating water pump, 20... Impeller, 21... Main shaft, 31, 32
...Main bearing (sliding bearing), 70,70'...Water pipe, IL...Impeller inlet level, LWL...Minimum water level.

Claims (1)

[Claim for Utility Model Registration] When an impeller is installed above the minimum water level specific to the pump and the water level falls below the impeller inlet level, at least before the water level falls below the minimum water level, The main body pump is capable of air operation by introducing air into the pump from between the lowest water level and the lowest water level, and the main shaft to which the impeller is attached is pivotally supported by a sliding bearing; A vertical shaft pump comprising: a lubricating water pump installed below the water level; and a water suction pipe that supplies water sucked by the lubricating water pump to a sliding bearing of the main pump as lubricating water. .