JP2673446B2 - Lubrication water supply method for bearing of vertical pump - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for supplying lubricating water to a bearing, which is particularly required during air operation in a vertical shaft pump used for a rainwater drainage pump or the like.

[Prior Art] Ceramic bearings, which have excellent wear resistance and can use self-pumped water as lubricating water, have recently been widely used as bearings for vertical axis pumps.

On the other hand, due to the rapid urbanization in recent years, the inflow of rainwater to the drainage pump station is becoming large and rapid, and the demand for the standby operation of the pump is increasing to cope with such a situation. However, in a vertical shaft pump that performs an air operation represented by such a standby operation, the state where the pump is started and the main shaft is rotating but the pump is not pumped continues for a long time. Since water was not injected, the ceramic bearing as described above could not be adopted as it was.

As a means to solve such a problem, it is possible to inject lubricating water into the bearing from the outside, but in this case it is meaningless to continue injecting water even after pumping has started, Will drive extra costs. Therefore, until now, by measuring the water level of the suction well, if the water level of this suction well is lower than the preset water level, i.e., the water level at which the vertical pump always pumps, the lubricating water is injected into the bearing. The method was taken.

[Problems to be Solved by the Invention] However, when the lubricating water is injected into the bearing based on the water level of the suction well as described above, generally, the water surface of the suction well is not always calm and wavy. In some cases, it was necessary to set the water level at which water injection was stopped to a high eye with a margin, in consideration of the fact that water might be present.

However, in such a case, when the water surface is relatively calm, pumping will be performed at a stage that has not reached the set water level for stopping the injection of the lubricating water, and in some cases, unnecessary supply of lubricating water will occur. There was a problem that it could be continued for a long time. That is, the above-described supply method for the bearing could not sufficiently achieve the purpose of preventing unnecessary water injection.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for supplying lubricating water to a bearing of a vertical shaft pump that can stop the injection of lubricating water to the bearing to a necessary minimum.

[Means for Solving the Problem] In order to achieve the above object, the method for supplying lubricating water to a bearing of a vertical shaft pump according to the present invention uses a full water detector to determine whether the uppermost bearing in the vertical shaft pump is flooded. If it is detected that the bearing is not submerged before the main spindle starts rotating, the lubricating water supply system is driven to inject the lubricating water into the bearing in the vertical shaft pump, and the main spindle rotates. After that, when it is detected that the uppermost bearing is submerged, the drive of the lubricating water supply system is stopped to stop pouring the lubricating water to the bearing, and it is detected that the uppermost bearing is not submerged. In this case, the lubricating water supply system is driven to inject the lubricating water into the bearing.

[Operation] By doing the above, if the uppermost bearing in the vertical shaft pump is not submerged before the main shaft starts rotating, lubricating water is injected from outside to each bearing. . Further, even after the main shaft is rotated, the above-mentioned uppermost bearing is not flooded, and the lubricating water is injected in the same manner as described above.
The supply of the lubricating water is stopped when the full water detector detects the infiltration.

[Example] Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 shows a vertical shaft pump for supplying lubricating water to a bearing by the method of the present invention. In FIG. 1, 1 is a main shaft of the vertical shaft pump connected to an electric motor (not shown),
Reference numerals 2 and 3 denote submersible bearings that support the main shaft 1 in the vertical shaft pump.

The main shaft 1 starts to rotate when a motor (not shown) is driven after a predetermined time has elapsed since a start switch (not shown) was pressed.

Each of the submersible bearings 2 and 3 is made of ceramics such as silicon carbide. Of these, the submerged bearing 2 is the uppermost bearing in the vertical shaft pump, and is provided at a position substantially corresponding to the floor surface position of the water absorption well. on the other hand,
The underwater bearing 3 is provided on the base 5 of the guide vane 4.

Lubricating water is supplied to these submersible bearings 2 and 3 through a water injection pipe 7 by operating a water injection pump 6 provided outside the vertical shaft pump. That is, the water injection pump 6 and the water injection pipe 7 together with a lubricating water source (not shown) constitute a lubricating water supply system.

On the other hand, the vertical shaft pump is equipped with a detection unit 8a of a full water detection tree above the floor surface F of the water intake well and above the underwater bearing 2, that is, on the downstream side. This full water detector 8
Is to start the detection operation by turning on the start-up switch 9 of the vertical shaft pump, and when the detection unit main body 8b which receives the detection signal from the detection unit 8a does not reach the detection level of the water in the vertical shaft pump. A non-full signal is output, and when the vertical pump starts pumping, the full pump signal is output when its own pumping level reaches the detection level. These signals are sent to the water injection pump 6.

The pump 6 operates when the signal received from the full water detector 8 is a non-full signal, and stops the operation when the signal is full.

This vertical pump also has a pump-specific minimum water level LWL that sucks air when the submersion depth of the suction port is less than this.
The impeller 10 is disposed above the portion corresponding to the above, and the intake port is opened below the inlet of the impeller 10 and an intake passage 11 in which a steam / water switching intake valve 12 is interposed is provided. Equipped. When the water level drops, the impeller entrance level IL
Intake valve 12 when the water level reaches a specified level between
By opening, the air is sent below the impeller 10 via the intake passage 11 to switch from pumping operation to air operation,
When the water level rises and the water level of the suction well reaches the impeller inlet level IL, the intake valve 12 is closed to switch the air operation to the pumping operation while sucking the residual air.

The vertical pump configured as described above controls the injection of lubricating water into the submersible bearings 2 and 3 in the following procedure.

First, the starting switch 9 of the vertical shaft pump is turned on. As described above, when the activation switch 9 is turned on, the full water detector 8 starts the detecting operation, but it is obvious that the detector 8a of the full water detector 8 is provided above the floor surface F of the water intake well. As described above, when the activation switch 9 is turned on, the detection unit main body 8b of the full water detector 8 generates a non-full water signal.

This non-filling signal is sent to the water injection pump 6, which causes the water injection pump 6 to start operating. Then, by the operation of the water injection pump 6, lubricating water is injected from the external water source (not shown) into the underwater bearings 2 and 3 through the water injection pipe 7.

That is, in the case of the vertical shaft pump shown in FIG. 1, when the starting switch 9 of the vertical shaft pump is turned on, the water injection pump 6 is activated, and after a time lag such as the time during which the lubricating water flows in the water injection pipe 7, a submersible bearing 2 is obtained. This lubrication water is poured into 3 and 3. By the way, as described above, the spindle 1 starts to rotate after the lapse of a predetermined time after the start switch 9 is turned on, but it is clear that the predetermined time is set to include the time lag.

By doing the above, when the electric motor connected to the main shaft 1 is driven and the main shaft 1 starts to rotate,
The submersible bearings 2 and 3 have already been reliably filled with lubricating water.

Next, when the main shaft 1 starts to rotate, the vertical shaft pump enters the operating state. In the vertical shaft pump, as described above, air is sent below the impeller 10 through the intake passage 11 so that the main shaft 1 It is possible to perform aerial operation in which water is not pumped even though is rotating. But,
No matter how the water level of the water intake well fluctuates during this air operation, the full water detector 8 generates a non-full water signal as long as the pumping is started and the detector 8a is not flooded. It continues to operate, and the submersible bearings 2 and 3 continue to be filled with lubricating water from the outside.

Next, when the vertical pump starts pumping and the submerged bearing 2 at the top is submerged by the pumped water, as long as the impeller 10 is rotating normally, the water in the vertical pump is immediately detected. The detection unit body 8b generates a full water signal.

Upon receiving this full signal, the water injection pump 6 stops operating, whereby the submersible bearings 2, 3 via the water injection pipe 7
Water injection to the is stopped. However, at this time, since the submersible bearings 2 and 3 are already submerged in the self-lifted water, no problem will occur even if the supply of the lubricating water from the outside is stopped.

According to the procedure described above, when the submerged bearings 2 and 3 are not submerged in the self-lifting water despite the rotation of the main shaft 1, the external lubricating water is surely supplied to the submersible water. bearing
Water can be poured into a few. Further, when the submersible bearings 2 and 3 are submerged in the self-lifted water, the pouring of the lubricating water can be promptly stopped. Therefore, unnecessary lubrication water is not injected, so that the power for this injection can be suppressed to a minimum, and the wear of the bearing can be reliably prevented.

In the method of the present invention, the bearing that supports the main shaft may be provided at three or more places, and the full water detector detects that the uppermost bearing in the vertical shaft pump is submerged in its own pumped water. Anything is acceptable. Further, the method of the present invention can be applied to any vertical shaft pump capable of performing air operation, but any method of performing air operation may be used.

[Effects of the Invention] As is clear from the above description, according to the method for supplying lubricating water to a bearing of a vertical shaft pump according to the present invention, the amount of lubricating water injected to the bearing can be minimized. In addition, the lubricating water and the power for pouring the lubricating water are saved, and the operating cost is reduced. In addition, even though the amount of external lubricating water injected can be minimized in this way, the bearings in the vertical shaft pump are constantly supplied with self-pumped water or external lubricating water, so bearing wear is required due to so-called dry operation. There is no such thing as going further.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a vertical shaft pump adopting the method of the present invention. 1 …… Spindle 2 …… Underwater bearing (uppermost bearing) 3 …… Underwater bearing (bearing) 6 …… Water injection pump (lubrication water supply system) 7 …… Water injection pipe (lubrication water supply system) 8 …… Full water detection vessel

Claims (1)

(57) [Claims] 1. A full water detector is used to detect whether or not the uppermost bearing in the vertical shaft pump is submerged, and when it is detected that the bearing is not submerged before the main shaft starts rotating. Drives the lubricating water supply system to inject lubricating water into the bearings in the vertical shaft pump, and stops the driving of the lubricating water supply system after detecting that the uppermost bearing is submerged after the main shaft is rotated. Stop the injection of lubricating water to the bearing, and if it detects that the uppermost bearing is not flooded, it drives the lubricating water supply system to inject lubricating water to the bearing. A method for supplying lubricating water to a bearing of a vertical shaft pump, which is characterized.