JPH0666286A - Vertical shaft pump - Google Patents

Abstract

PURPOSE:To provide a vertical shaft pump whose equipement for maintaining the lubricating performance of submerged bearings is simple and with which there is no danger of causing water pollution, etc. CONSTITUTION:Submerged bearings 14, 16 and a main spindle 12 are all covered with a shaft protecting pipe 18, the lower end portion of the pipe 18 being freely rotated and made watertight by a mechanical seal 20. The shaft protecting pipe 18 is filled with an aqueous solution 30 of gricole. Since the shaft protecting pipe 18 is filled with the aqueous solution 30 of gricole, it is easily installed. Further, even if the aqueous solution 30 of gricole leaks, it is not poisonous to fishes and does not cause water pollution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical shaft pump in which a main shaft is rotatably supported by a submersible bearing, and the submersible bearing and the whole main shaft are covered with a shaft protection tube so that the main shaft and the submersible bearing do not come into direct contact with pumped water. It is about.

[0002]

2. Description of the Related Art In a conventional vertical shaft pump that uses a submersible bearing to rotatably support a main shaft and covers the submersible bearing and the main shaft with a shaft protection tube, fresh water is always injected into the shaft protection tube. There is one that ensures the lubrication of the submersible bearing by causing it to flow out and filling the inside with clean water. In such an apparatus, it is necessary to continuously inject fresh water during operation of the vertical shaft pump, which consumes a large amount of fresh water, and moreover, piping and pump equipment for injecting this fresh water are required.
Further, if the water injection system is disturbed, the submerged bearing is immediately burned, which causes a serious failure that the vertical shaft pump cannot be operated.

Therefore, it has been proposed that the lower end of the shaft protection pipe is provided with a mechanical seal such that the main shaft is rotatable and has a watertight structure, and the shaft protection pipe is filled with lubricating oil such as turbine oil. . Compared to the one that always fills with fresh water, the attached equipment is simpler and the failure of the vertical axis pump is less likely to occur, resulting in higher reliability.

[0004]

In the above device for filling the shaft protection tube with lubricating oil, if oil leaks from the mechanical seal or the like, it immediately causes water pollution. Therefore, there was a problem that maintenance inspection and repair of the mechanical seal had to be performed frequently.

The present invention has been made in view of the circumstances of such a conventional device, and provides a vertical shaft pump which has a simple facility for maintaining the lubricating performance of a submersible bearing and which does not cause water pollution or the like. The purpose is to do.

[0006]

In order to achieve the above object, the structure of the vertical shaft pump according to the present invention is such that the main shaft is rotatably supported by the submersible bearing, and the submersible bearing and the main shaft are entirely protected by the shaft protection tube. In a vertical shaft pump that is covered with a main shaft and a submersible bearing so as not to come into direct contact with pumped water, a seal member is arranged at the lower end of the shaft protection tube so that the main shaft is rotatable and has a watertight structure. The shaft protection tube is filled with an aqueous glycol solution.

A storage tank, which communicates with the shaft protection tube and stores the glycol aqueous solution, is arranged at a position higher than the height of the upper end of the shaft protection tube, and the water level of the glycol aqueous solution is stored in the storage tank. Water level sensor means for issuing an alarm when the water level drops below a predetermined level may be provided.

[0008]

[Operation] According to the results of experiments by the inventors, the aqueous glycol solution has the same lubricity and rust prevention effect as turbine oil with respect to a submerged bearing made of ferrous metal. Even if it leaks, it will not be diluted to cause acute toxicity to fish, and there is no risk of causing problems such as water pollution.

If a storage tank communicating with the shaft protection tube is provided at a position higher than the height of the upper end of the shaft protection tube and a water level sensor means is provided in this storage tank, the glycol aqueous solution may leak in the unlikely event. The refilling of the shaft protection tube from the storage tank does not cause seizure of the underwater bearing, and the leakage can be detected from the drop in the water level.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a vertical sectional view of an embodiment of a vertical shaft pump of the present invention.

In FIG. 1, a vertical shaft pump 10 is a main shaft 1.
2 is rotatably supported by submerged bearings 14 and 16. And these submersible bearings 14 and 16 and this main spindle 1
The whole 2 is covered with a shaft protection tube 18, the lower end of which is rotatably and watertightly sealed by a mechanical seal 20 as a sealing member, and the upper end of which is similarly rotatably and watertightly sealed by a protective cover 22. Be stopped. Further, the storage tank 24 is arranged at the height of the upper end portion of the shaft protection pipe 18 (or a position higher than this), and the shaft protection pipe 18 is communicated with the supply pipe 26, and the water level in the storage tank 24 is measured. A water level sensor means 28 is provided to generate an alarm or the like when the water level drops below a predetermined level. And glycol aqueous solution 30
Is filled in the shaft protection pipe 18 and is stored in the storage tank 24 at a water level equal to or higher than a predetermined level. As this glycol aqueous solution 30, for example, an aqueous solution having a concentration of 30% (vol%) is used, but a glycol solution having a concentration of 25 to 60% can be sufficiently used. An aqueous solution having a concentration of 60% or more is not suitable because the antifreeze effect is reduced.

In such a structure, the underwater bearings 14, 16
Is immersed in the glycol aqueous solution 30, and proper lubrication performance can be obtained. Then, it suffices to fill the shaft protection tube 18 with the glycol aqueous solution 30, and the equipment for maintaining the lubrication performance of the underwater bearings 14 and 16 becomes simple. In addition, even if the glycol aqueous solution 30 leaks from the mechanical seal 20, the leaked portion is supplied from the storage tank 24 and the submersible bearings 14 and 16 are always kept immersed in the glycol aqueous solution 30 and lubricated. There is no loss of sex. Further, when the water level in the storage tank 24 becomes lower than a predetermined level due to the leakage of the glycol aqueous solution 30, an alarm is immediately issued from the water level sensor means 28. Therefore, the maintenance manager can easily know that the glycol aqueous solution 30 is leaking. In particular, when the amount of leakage is large and the aqueous glycol solution 30 is suddenly lost, the abnormality can be quickly recognized, and a serious accident such as the vertical pump 10 becoming inoperable can be prevented in advance. .

By the way, the inventors of the present invention have manufactured submerged bearings of iron-based metal and, while soaking them in a glycol aqueous solution and turbine oil, apply a load to the sliding contact surfaces to continuously slide them. When a wear test was carried out with each of them, it was confirmed that any of them did not cause abnormal wear on the abutting surface and had the same lubricating performance.

Further, when submerged bearings made of iron-based metal were immersed in a glycol aqueous solution, turbine oil and distilled water as fresh water to examine the occurrence of rust, the submerged bearings immersed in distilled water took 1 hour. Although it rusted later, it was 1 for submerged bearings immersed in glycol aqueous solution and turbine oil.
No rust was seen even after a lapse of months. Therefore, it was confirmed that the glycol aqueous solution has the same rust prevention effect as turbine oil.

Further, in order to investigate the toxicity of the glycol aqueous solution, assuming that the glycol aqueous solution leaks,
When test fish were added to the test solution diluted with fresh water to a glycol concentration of 1500 mg / 1 liter and constantly aerated, dead fish did not occur even after 4 days. From this, it was confirmed that even if the glycol aqueous solution were to leak, there was no acute toxicity to fish. Then, the glycol aqueous solution is finally biodegraded in nature even if it leaks.
Therefore, the glycol aqueous solution is highly safe as compared with turbine oil, without the risk of causing environmental pollution such as water pollution.

In the above embodiment, the shaft protection tube 1
Although the lower end of 8 has a watertight structure by the mechanical seal 20, it is not limited to such a structure, and any seal member may be used as long as the main shaft 12 is rotatable and has a watertight structure. Further, the water level sensor means 28 may be any one as long as it generates a signal when the water level falls below a predetermined level, and gives the signal to a control device (not shown) of the vertical shaft pump 10 so that the control device appropriately processes. You can also

[0017]

As described above, since the vertical shaft pump of the present invention is constructed, the following special effects are obtained.

In the vertical shaft pump according to the first aspect of the present invention, since the shaft protection tube is filled with the glycol aqueous solution, the submersible bearing has the same lubricating performance as when the turbine oil is filled, and the lubricating performance is maintained. The equipment for doing so is simple, and even if it leaks, it will not cause water pollution or the like, will not cause environmental pollution, and is highly safe.

Further, in the vertical shaft pump according to the second aspect, even if the glycol aqueous solution leaks, it is replenished and supplied from the storage tank into the shaft protection pipe, and the lubricating performance of the submersible bearing can be maintained. Then, the leakage can be detected by the water level sensor means due to the decrease in the water level, and the abnormality can be dealt with before a serious accident such as the inability to operate the vertical shaft pump occurs, and the maintenance management is accordingly easy.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of a vertical shaft pump of the present invention.

[Explanation of symbols]

 10 Vertical Pump 12 Spindle 14, 16 Underwater Bearing 18 Shaft Protective Tube 20 Mechanical Seal 24 Storage Tank 28 Water Level Sensor Means 30 Glycol Aqueous Solution

Claims (2)

[Claims] 1. A vertical shaft pump in which a main shaft is rotatably supported by a submersible bearing, and the submersible bearing and the main shaft are entirely covered by a shaft protection tube so that the main shaft and the submersible bearing do not come into direct contact with pumped water. A vertical shaft pump, wherein a seal member is arranged at a lower end portion of the shaft protection pipe so that the main shaft is rotatable and has a watertight structure, and a glycol aqueous solution is filled in the shaft protection pipe. 2. The vertical shaft pump according to claim 1, wherein a storage tank communicating with the shaft protection pipe and storing the glycol aqueous solution is arranged at a position higher than the height of the upper end of the shaft protection pipe. A vertical axis pump, characterized in that the storage tank is provided with water level sensor means for issuing an alarm when the water level of the aqueous glycol solution drops below a predetermined level.