JPH0422796A - Detecting method for operating condition of pump and supply method of lubricating water to pump bearing - Google Patents

Abstract

PURPOSE:To accurately detect operating condition of a pump by arranging a plurality of terminal parts of a detecting power circuit having conductive medium of self pumping water on a plurality of detecting positions in the pump, and detecting the operating condition based on open/close of the detecting power circuit. CONSTITUTION:In the operating condition of a vertical shaft pump 1 of which a main shaft 2 is driven, at the water level of a sucking water well over a pumping beginning water level HWL, the suction valve 17 of a suction pipe 18 is closed, water is sucked up with a vane wheel 3, and pumping operation is performed. At this time, a first terminal part 12 and a second terminal part 14 are electrically conducted through self pumping water as conductive medium to close a detecting power circuit 15, and hence pumping operation is displayed on an indicator 16. When the water level is lowered in proximity to a pumping cut off water level LWL, the suction valve 17 is opened to feed air to the inlet 3a of the vane wheel 3, and operation is changed over to aerial operation. Then, electric conduction between the first and second terminal parts 12,14 is dissolved to open the detecting power circuit 15.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for detecting the operating status of a pump installed in a drainage pump station installed in a waterway and used for draining rainwater, and a bearing for the pump. This invention relates to a method of supplying lubricating water.

[Prior Art] For example, ceramic bearings are used as bearings in vertical shaft pumps, which are lubricated and cooled by self-pumped water and can continue stable operation.

In this type of bearing, dry operation is performed for a very short time immediately after the pump is started, and after this short time +111 has elapsed, the bearing is immediately lubricated and cooled by self-pumped water and enters stable operation. That is, with ceramic bearings, dry operation is limited to a short period of time.

On the other hand, with the rapid progress of urbanization, the amount of rainwater flowing into pumping stations installed in waterways is rapidly increasing in volume. In this situation.

Even if the water level in the water intake well at the drainage pump station falls below the pumping cut-off water level of the indoor shaft pump, this can be handled by continuing dry operation and performing advance standby operation or air control operation that precedes the operation status of the pump. The indoor shaft pump used for the advance standby operation and the air management operation continues to operate dry for a long time, and during this period, no lubricating water is supplied to the bearings. Therefore, it has not been possible to use ceramic bearings, which limit the dry operation time to a short time, for indoor shaft pumps that perform advance standby operation or air control operation.

In order to solve this problem, it is possible to supply lubricating water to the bearing from the outside, but in this case, it is not possible to continue supplying lubricating water from the outside even during pumping operation. It's meaningless. Therefore, by measuring the water level in the water suction well, there is a method for supplying lubricating water to the bearings when the water level drops to a preset water level, that is, lower than the pumping start water level of the chamber shaft pump. He had been hired.

[Problems to be Solved by the Invention] However, with this method of supplying lubricating water to the bearings based only on the water level lower than the pumping start water level of the water absorption well, it is difficult to solve the problem when the water surface of the water absorption well is calm. Since it is necessary to take into account the case where the water is undulating, it is usually necessary to set the water level at which the lubricating water supply is stopped to a high level with some margin.

However, in such a control method, when the water surface is relatively calm, lubricating water is supplied even though pumping operation is in progress. In other words, it is not possible to accurately know the operating status of the pump, and as a result, the wasted supply of lubricating water continues for a long time, making it impossible to eliminate unnecessary water injection into the bearings.

The present invention was made in view of the above circumstances, and provides a method for detecting the operating status of a pump that can accurately detect the operating status of the pump, as well as a method that ensures the supply of lubricating water to the bearings and minimizes the necessary amount. The object of the present invention is to provide a method for supplying lubricating water to the bearings of a pump that can be controlled.

[Means for Solving the Problems] In order to achieve the above object, the first invention provides self-pumped water as an energizing medium at a first detection position between the pump-specific pumped water cutoff water level and the pump impeller inlet. A first terminal portion of the detection power supply circuit is arranged at a second detection position above the pump impeller, and the operating status is detected based on opening and closing of the detection power supply circuit. It was designed to do so.

Further, the second invention provides a first terminal portion of a detection power supply circuit that uses self-pumped water as an energizing medium at a first detection position between the pump-specific pumped water cutoff water level and the pump impeller inlet, and A second terminal portion of the detection power supply circuit is disposed at a second detection position above the vehicle, and the stoppage of supply of lubricant water from the lubricant water supply system to the bearing of the pump main shaft is controlled based on opening and closing of the detection power supply circuit. This is what I did.

[Function] According to the present invention, when pumping operation is being performed, the first terminal portion and the second terminal portion are electrically connected to each other by using the self-pumped water as a current-carrying medium to close the detection power supply circuit, and to adjust the water level. If the water level has dropped to near the pumping start water level and submerged operation is being performed,
Electrical continuity between the first terminal portion and the second terminal portion, which use the self-pumped water as a current-carrying medium, is broken to open the detection power supply circuit. In other words, the operational status of the pump, such as pumping operation or submersible operation, can be determined by opening and closing the detection power supply circuit.
By knowing whether the pump is in pumping operation or submerged operation, lubricating water can be supplied from the lubricating water supply system to the pump main shaft bearing during submerged operation, and the supply of lubricating water can be stopped during pumping operation. can do.

[Example] Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a chamber shaft pump to which the present invention is applied. In the figure, the main shaft 2 of the chamber shaft pump 1 has a bearing 4 fixed to the base of a guide vane 3A above an impeller 3, and a water suction pipe 5. It is rotatably supported by a bearing 8 that is fixed at approximately the same height as the floor 7 of the well 6, and is rotationally driven by a prime mover (not shown).

The bearings 4.8 are each made of ceramics such as silicon carbide, and are each provided with a lubricating water supply system 9.
Lubricant water for lubrication and cooling is supplied from the

The lubricating water supply system 9 includes a lubricating water supply source 9A, a pipe line 9B that communicates the lubricating water supply source 9A with the bearings 4 and 8, and a valve such as a solenoid valve or an electric pole valve interposed in the pipe line 9B. It is composed of 9C. Therefore, when the valve 9C is opened, lubricating water is supplied from the lubricating water supply source 9A to the bearings 4 and 8, and when the valve 9C is closed, the supply of lubricating water to the bearings 4 and 8 is stopped.

A first terminal portion 12 is installed in the suction side casing 11 at a first detection position 10 (for example, a pumping start water level HWL) between the pumping cutoff water level LWL specific to the chamber shaft pump l and the inlet 3a of the impeller 3.
The second terminal portion 14 faces the pumped water v5 at the second detection position 13 above the impeller 3. These first and second terminal portions 12.14 are connected to a detection power supply circuit 15 that uses self-pumped water as a current-carrying medium.

The output signal C from the detection power supply circuit 15 is input to the display 16 and displayed, and the detection power supply circuit 15 outputs a valve closing signal sh that closes the valve 9C during the closed pumping operation,
The detection power supply circuit 15 outputs a valve closing signal Op to open the valve 9C during the open air operation.

In addition, in this chamber shaft pump 1, if the depth of the water inlet is less than this, the lowest water level LWL unique to the pump will suck in air.
The impeller 3 is arranged above the 1 impeller 3.
An intake pipe 18 is provided which opens below the inlet 3a of the engine, that is, into the impeller chamber, and has an air/water switching intake valve 17 interposed therebetween.

Therefore, when the water level drops and the water intake level reaches the lowest water level (pumping cutoff water level) LWL specific to the pump, the intake valve 1
7 is opened to send air to the inlet 3a of the impeller 3 to switch from pumping operation to submerged operation, and when the water level rises, when the water level in the water intake well 6 reaches the level HWL of the inlet 3a of the impeller 3, the intake valve 17 is closed and the remaining air is sucked up while switching from air operation to pumping operation.

The opening and closing of the intake valve 17 is determined by the pumping start water level HWL or the pumping cutoff water level L using a water level gauge (not shown).
This is done based on a signal that is detected from WL and output to the intake valve 17.

Next, a method for detecting the operating status of the chamber shaft pump and a method for supplying lubricating water to the bearings 4 and 8 will be explained.

In the operating state of the chamber shaft pump l in which the main shaft 2 is rotationally driven, if the water level of the water suction well 6 is equal to or higher than the pumping start water level HWL, the intake valve 17 of the intake pipe 18 is closed, and the impeller 3 Pumping operation is performed because water is sucked up. In this case, the first terminal part 12 and the second terminal part 14 are electrically connected to each other by using the self-pumped water as a current-carrying medium, and the detection power supply circuit 5
Since the signal C outputted from this is inputted to the display 16 and displayed, it can be known that the indoor shaft pump 1 is in pumping operation.

On the other hand, since the detection power supply circuit 15 outputs the valve closing signal sh and the valve 9C is closed, the bearings 4 and 8 are lubricated and cooled by the self-pumped water sucked up by the impeller 3.

Even if the water level drops below the pumping start water level HWL due to continued pumping operation, the intake valve 17 remains closed until the water level drops to the pumping cutoff water level LWL, and the bearings 4, 8, lubrication and cooling are provided.

When the water level drops to around the pumping cutoff water level LWL, the intake valve 1
7 is opened to send air into the inlet 3a of the impeller 3, and the pumping operation is switched to the air operation. During this submerged operation, the electrical continuity between the first terminal section 12 and the second terminal section 14, which use self-pumped water as the energizing medium, is broken, so the detection power supply circuit 15 is opened. As a result, the signal C input from the detection power supply circuit 15 to the display 16 is converted and displayed, and it can be known that the indoor shaft pump 1 is in air operation.

In addition, since the detection power supply circuit 15 outputs the valve opening signal Op and the valve 9C is opened, the lubricating water supply system 9 supplies the bearings 4 and 8.
Lubricating water is supplied to the bearing 4.8 to lubricate and cool the bearing 4.8. Therefore, even if the indoor shaft pump is switched to submerged operation and the bearings 4 and 8 are no longer lubricated by self-pumped water, stable operation will continue because the lubricating water supplied from the lubricating water supply system 9 will lubricate them. As the submerged operation continues, the water level in the water intake well 6 rises,
When the pumping start water level HWL is reached, the pumping operation is switched to as described above, and the bearings 4 and 8 are lubricated by the self-pumping water.

In this way, during submerged operation of the indoor shaft pump l, the bearing 5.8 is lubricated and cooled by the lubricating water supplied from the lubricating water supply system 9, so that the dry operation continues for a long period of time. The ceramic bearing 5.8 can also be employed in the chamber shaft pump 1 that performs operation and air management operation.

It goes without saying that the present invention is applicable not only to the chamber shaft pump 1 described in the above embodiment, but also to other pumps capable of air operation.
3 may be located above the outlet 3b of the impeller 3.

[Effects of the Invention] Since the present invention is configured as described above, it produces the following effects.

According to the method for detecting the operating status of a pump according to claim (1), the detection power supply circuit is opened and closed in response to the presence or absence of electrical continuity between the first terminal portion and the second terminal portion, which use self-pumped water as a current-carrying medium. It is possible to accurately detect pi-turn situations such as pump pump operation and submerged operation.

According to the method for supplying lubricating water to the bearings of a pump according to claim (2), it is possible to know whether the pump is cartwheeling or being operated in air by opening and closing the detection power supply circuit. During pumping operation when the bearings can be lubricated by self-pumped water, the lubricating water supply system is closed, and during air operation when the bearings cannot be lubricated by self-pumped water, the lubricating water supply system is opened and The supplied lubricating water lubricates and cools the bearing, allowing stable operation to continue. Therefore, ceramic bearings can be used even in pumps that perform advance standby operation and air control operation, which were conventionally considered impossible, and improved versatility can be achieved. Furthermore, since the amount of lubricating water supplied to the bearing can be suppressed to the necessary minimum, it is possible to achieve savings in lubricating water and power for supplying the lubricating water.

[Brief explanation of drawings]

The drawing shows an embodiment of a chamber shaft pump to which the present invention is applied.
It is a schematic configuration diagram. 1... Pump (chamber shaft pump) 2... Main shaft 3... Impeller 3a... Impeller inlet 3b... Impeller outlet 4... Impeller inlet 488... Bearing 9... Lubricating water supply system 10... First detection position 12... ff1l terminal section 13... Second detection position 14... Second terminal section HWL... Pumping start water level LWL... Pumping water cutoff water level patent applicant Kubota Corporation

Claims (2)

[Claims] (1) The first terminal of the detection power supply circuit, which uses self-pumped water as the energizing medium, is arranged at the first detection position between the pump-specific pumped water cutoff water level and the pump impeller inlet, and the 1. A method for detecting operating status of a pump, characterized in that a second terminal portion of the detection power supply circuit is disposed at a second detection position, and the operating status is detected based on opening/closing of the detection power supply circuit. (2) The first terminal of the detection power supply circuit, which uses self-pumped water as the energizing medium, is arranged at the first detection position between the pump-specific pumped water cutoff water level and the pump impeller inlet, and the 2. A second terminal portion of the detection power supply circuit is disposed at the detection position, and the supply of lubricant water to the bearing of the pump main shaft is controlled to be stopped from the lubricant water supply system based on the opening and closing of the detection power supply circuit. A method for supplying lubricating water to pump bearings.