JPH06101685A - Vertical shaft pump - Google Patents

Abstract

PURPOSE:To filter out foreign matters in pumping up water and prevent a bearing from functional loss caused by biting the foreign matters in an in-tank type vertical shaft pump by covering a rotary shaft and a submerged bearing with a protective tube having a filter function. CONSTITUTION:In a vertical shaft pump, after water pumped up is sucked from a bell mouth of a pump casing 1 and further boosted up by an impeller 2 connected to a pump shaft 4, the water rises in a column 6. A bearing 9 for the pump shaft 4 is lubricated by the water pumped up in the column pipe 6. In this case, the pump shaft 4 and bearing 9 are covered with a protective tube 12 having a filter function, so that foreign matters are filtered during pumping up the water to prevent the bearing 9 from the functional loss caused by biting the foreign matters.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-tank vertical shaft pump, and more particularly to a seawater pump for thermal power or nuclear power plants.

[0002]

2. Description of the Related Art A conventional in-tank vertical shaft pump is disclosed in Japanese Patent Laid-Open No. 58-85.
As described in JP-A No. 393 or JP-A-62-67297, a method is used in which pumped water is used as it is as bearing lubricating water, or a method in which bearing lubricating water is supplied from the outside of the pump.

First, an embodiment in which pumped water from a pump is directly used as bearing lubricating water will be described with reference to FIG.

The pump is mounted in a pump casing 1 having a built-in impeller 2, a bell mouth 3 attached to the casing 1, a pump shaft 4 connected to the impeller 2, a drive unit 5 directly connected to the pump shaft 4, and a casing 1. The column pipe 6, a discharge casing 7 attached to the column pipe, a bearing bracket 8 attached above the liquid level in the column pipe 6, and a bearing 9 attached to the bearing bracket 8 to support the pump shaft 4, The bearing 9 is lubricated by pumping water of the pump itself which is pressurized by the impeller 2 and flows upward in the column pipe 6.

Next, an embodiment in which the bearing lubricating water is supplied from the outside of the pump will be described with reference to FIG. In addition to the pump structure described in FIG. 1, the pump includes a pump shaft 4 and a bearing 9.
A protective cylinder 12 is provided to cover the bearing lubrication water, and the bearing lubricating water is supplied from a separately provided water supply source to a water supply motor operated valve 13, a current detector 14,
Water is supplied into the protective cylinder 12 through the flow relay 15, the flow rate adjusting valve 16, etc., and after lubricating the bearing 9, it is discharged from the lower part of the protective cylinder 12 to the suction side of the impeller 2. In addition, 17 is an oil gliding water supply line, 18 is a switching valve,
19 is a timer.

[0006]

In the embodiment shown in FIG. 1 in which the pumped water of the pump is used as it is as the bearing lubricating water, the pumped water of the pump is directly supplied to the bearing 9 as the bearing lubricating water. It is assumed that an object may be caught in the bearing 9 and hinder the sound operation of the pump.

Further, in the embodiment shown in FIG. 2 in which the bearing lubricating water is supplied from the outside, if a filtering mechanism is provided in the bearing lubricating water supply line, it is possible to easily remove impurities, but a small-diameter pipe. Since the bearing lubrication water is supplied from the line, there is a problem that when the seawater is handled, the supply line may be blocked and supply of the bearing lubrication water may be impossible due to the adhesion of marine organisms. ..

The object of the present invention is to provide the bearing 9 with lubricating water that is controlled to be free of contaminants without providing equipment for supplying the bearing lubricating water to the outside of the pump. An object of the present invention is to provide an in-tank vertical shaft pump capable of monitoring the supply state of.

[0009]

In order to achieve the above object, the present invention covers the pump shaft 4 and the bearing 9 with a protective cylinder 12 having a filtering mechanism to prevent foreign matters from being pumped into the bearing 9. A pressure difference measuring device is provided between the inside and the outside of the protective cylinder 12 so that the protective cylinder can be monitored for clogging.

[0010]

The function of the above technical means is as follows.

Even if contaminants are sucked into the pump during pump operation, the protective cylinder 12 having a filtering function for covering the pump shaft 4 and the bearing 9 is provided inside the protective cylinder 12 used as bearing lubricating water. Since pumped water from which impurities have been removed is supplied, the facility for supplying clean bearing lubricating water from the outside is unnecessary.

A differential pressure measuring device for monitoring the pressure difference between the inside and the outside of the protection cylinder 12 monitors the clogging state of the filtration mechanism of the protection cylinder 12 due to impurities in the pumped water or sea life when the pump is operating. As a result, the supply state of the bearing lubricating water can be monitored.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG.

In addition to the structure of the embodiment of the prior art shown in FIG. 1, the pump covers the pump shaft 4 and the submersible bearing 9 with a protective cylinder 12 made of metal mesh or a perforated plate and having a filtering function.

The pumped water is sucked from the bell mouth 3, pressurized by the impeller 2, and then rises in the column pipe 6. At this time, pumped water also flows into the protective cylinder 12, rises in the protective cylinder 12 as well as outside the protective cylinder 12, and is used as lubricating water for the bearing 9. Here, since the protective cylinder 12 is made of a wire mesh, a perforated plate or the like having a filtering function, the protective cylinder 12 is protected even if there are impurities in the pumped water.
The bearing 9 is lubricated by the pumped water from which impurities are removed.

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

In FIG. 4, 4 is a pump shaft, 9 is an underwater bearing, 6 is a casing, 12 is a protective cylinder having a filtering function such as a wire mesh or a perforated plate, and 21 is a differential pressure measuring device.

The differential pressure measuring device is mounted so that the pressure difference between the inside and the outside of the protective cylinder can be measured. If the protective cylinder is not clogged during pump operation, the differential pressure will be 0, but due to impurities in the pumped water. When the protective cylinder is clogged, the flow rate of pumped water in the protective cylinder is slower than that in the outer side of the protective cylinder, and a pressure difference occurs, so that the clogging is monitored by measuring the differential pressure.

[0019]

According to the present invention, the bearing 9 is supplied with the lubricating water which is controlled so as not to contain impurities, without providing the equipment for supplying the bearing lubricating water outside the pump. Further, it is possible to monitor clogging of the protective cylinder.

[Brief description of drawings]

FIG. 1 is a sectional view of a vertical shaft pump showing a conventional technique.

FIG. 2 is a control system diagram of a conventional vertical shaft pump that supplies bearing lubricating water from the outside of the pump.

FIG. 3 is a sectional view of a vertical shaft pump according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of a vertical shaft pump according to an embodiment of the present invention.

[Explanation of symbols]

4 ... Pump shaft, 6 ... Column pipe, 9 ... Bearing, 12 ... Protective tube, 21 ... Differential pressure measuring device.

Claims (1)

[Claims] 1. An in-tank vertical shaft pump, wherein a rotary shaft and a submersible bearing are covered with a protective cylinder having a filtering function.