JPH0419392A - Method for detecting operation condition of pump and method for supplying lubricating water to bearing of pump - Google Patents

Abstract

PURPOSE:To precisely detect an operation condition of a pump by providing two detected parts with an interval in an axial direction on a transmission shaft which transmits an output of a motor to the pump, and detecting relative positional displacement between both detected parts. CONSTITUTION:In a device wherein a vertical shaft pump 1 is rotationally driven by a motor 10 such as an engine, fist and second disc plates 16, 18 are provided with an interval in an axial direction on a transmission shaft 14 for transmitting an output of the motor 10 to a main shaft 2 of the pump l, which plates 16, 18 have detected parts 15, 17 composed of slits. First and second detectors Ca, Cb composed of optical sensors, etc., are oppositely provided respectively on the detected parts 15, 17. The signals from the detectors are input to a detecting circuit 19. A lap period S during which detected periods Sa, Sb of the detectors Ca, Cb overlap each other is detected and input to a comparing circuit 21. When the lap period S is less than a first set value S1, 'pumping' is displayed on a display 33. When the lap period S is more than a second set value S2, 'waiting' is displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of detecting the operating status of a pump and a method of supplying lubricating water to the bearings of the pump.

[Conventional technology]

For example, ceramic bearings are used as bearings for indoor shaft pumps, which are lubricated and cooled by self-pumped water and can continue stable operation.

This type of bearing operates dry for a very short period of time immediately after the pump is started, and after this short period of time, it is immediately lubricated and cooled by self-pumped water and begins stable operation. That is, with ceramic bearings, trial operation is limited to a short time.

On the other hand, with the rapid progress of urbanization, the amount of rainwater flowing into pumping stations located along waterways is rapidly increasing. In such a situation, even if the water level in the water intake well at the pumping station drops below the pumping cutoff level of the indoor shaft pump, dry operation is continued, and advance standby operation or air management operation that precedes the pump operation status is recommended. In the soybean cake pump used for the preceding standby operation and the air management operation, dry operation continues for a long time, and during this period, no lubricating water is supplied to the bearings.

Therefore, it has not been possible to use a ceramic bearing, which limits the dry operation time to a short time, in a soybean cake pump that performs advance standby operation or air management operation.

One possible solution to this problem is to supply lubricating water to the bearing from the outside, but in this case, it is pointless to continue supplying lubricating water from the outside even during pumping operation. It is. Therefore, by measuring the water level in the water suction well, a method has been adopted in which lubricating water is supplied to the bearings when the water level drops to a preset water level, that is, lower than the water level at which the bean cake pump starts pumping. It had been.

[Problem to be solved by the invention] However, in this method of supplying lubricating water to the bearing based on the water level of the water absorption well, cases where the water surface of the water absorption well is calm and undulating are taken into consideration. It was necessary to set the lubricating water supply stop level to a high level with some margin in consideration of the situation where the water is rippled.

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 was not possible to accurately know the operating status of the pump, and as a result, the wasted supply of lubricating water continued for a long time, making it impossible to prevent unnecessary water injection into the bearings. .

In view of these circumstances, the present invention was made by focusing on the fact that the torsion of the transmission shaft that transmits the output of the prime mover to the pump changes due to fluctuations in torque during pumping operation and submerged operation. A pump operating status detection method that can accurately detect the pump operating status, and a pump bearing that can reliably control the supply of lubricating water to the bearing to the minimum necessary level. The purpose is to provide a lubricating water supply method for

[Means to solve the problem]

In order to achieve the above object, a first invention provides a transmission shaft that transmits the output of a prime mover to a pump, and a first and a second detected portion are provided spaced apart in the axial direction of the transmission shaft, and and a second detected part, respectively, and output first and second detection signals, and the operating status of the pump is detected based on both of the detection signals. be.

A second invention provides a transmission shaft that transmits the output of a prime mover to a pump, and a first and a second detected portion are provided spaced apart in the axial direction of the transmission shaft, and the first and second detected portions are respectively provided. First and second detectors are provided for detecting and outputting first and second detection signals, and based on both of the detection signals, the supply of lubricating water from the lubricating water supply system to the bearing of the pump main shaft is controlled to be stopped. This is what I did.

[Effect]

According to the present invention, the larger the shaft power of the pump, the thicker (twisted) the transmission shaft that transmits the output of the prime mover to the pump. relative position shift in the direction of rotation, and a phase difference occurs in the outputs from the first and second detectors.On the other hand, the shaft power and discharge amount of the pump have a fixed relationship depending on the type of pump and installation conditions. Therefore, if the characteristics of the pump are investigated in advance, it is possible to know whether the pump is in pumping operation or not, and the operating status such as the discharge amount, from the outputs from the first and second detectors.

In addition, since it is possible to know whether the pump is in pumping operation or submerged operation, it is possible to supply lubricating water during submerged operation, and to stop supplying lubricating water during pumping operation, based on the upper distribution detection signal. I can do it.

〔Example〕

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

FIG. 1 shows a soybean cake pump to which the present invention is applied. In the figure, the main shaft 2 of the soybean cake pump 1 has a bearing 5 fixed to the base of a guide vane 4 above an impeller 3, and a floor surface 7 of a water suction well 6. It is rotatably supported by a bearing 8 fixed at substantially the same height level, and is rotationally driven by a prime mover 10 such as a motor or an engine.

The bearings 5.8 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 supplies lubricating water from the lubricating water supply source 9A to the bearings 5 and 8,
It is constituted by a valve 9C, such as a solenoid valve or an electric ball valve, which is interposed in this conduit 9B.

Therefore, when the valve 9C is opened, lubricant water is supplied from the lubricant water supply source 9A to the bearings 5 and 8, and when the valve 9C is closed, the supply of lubricant water to the bearings 5 and 8 is stopped.

The transmission shaft 14 that transmits the output of the prime mover 10 to the main shaft 2 of the pump 1 has a first disc 16 having a first detected part 15 made of a slit, and a second detected part 17 made of a slit. A second disk 18 is provided spaced apart from each other in the axial direction of the transmission shaft 14 .

The first and second detected parts 15.17 are provided with first and second detectors Ca and Cb facing each other, respectively. The first and second detectors (, a, and Cb are for detecting the first and second detected parts 15 and 17, respectively, and are, for example, reflective optical sensors integrally equipped with a light emitter and a light receiver). When the transmission shaft 14 is rotating with no load applied to the transmission shaft 14, the first and second detectors Ca and Cb each have the following characteristics:
The first and second detected parts 1517 are arranged to be detected simultaneously, and the first and second detection signals a,
b is output to the detection circuit 19.

When a load is applied to the transmission shaft 14, the transmission shaft 14 is twisted, so the first and second detectors Ca.

The first and second detection signals a and b detected by cb are out of phase as shown in FIG. The detection circuit 19 detects the detection time Sa of the first and second detectors Ca and Cb.

It detects the lap time S when sb wraps,
The wrap signal C of the wrap time S is output to the comparator circuit 21 in FIG.

The comparison circuit 21 receives the first set value S1 or the second set value S2 from a setter 22 including a selector. The comparison circuit 21 compares the lap time S and the first set value S1.
If the lap time S is smaller than the first set value S1, a closing signal sh is output to close the valve 9C during pumping operation, and at the same time, the display 33 indicates that "pumping is in progress". , display. On the other hand, the comparison circuit 21 compares the wrap time S and the second set value S2, and compares the wrap time S with the second set value S2.
is larger than the second set value S2, that is, during submerged operation, a valve opening signal Op is output to open the valve 9C, and at the same time, the display 33 is made to display that it is "on standby". In addition,
The first set value Sl is smaller than the second set value S2.

The detection circuit 19, comparison circuit 21, and setting device 22 are incorporated into one control device 120.

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 disposed above the impeller 3.
An intake pipe 13 is provided which opens below the inlet of the engine, that is, into the impeller chamber, and has an air/water switching intake valve 12 interposed therebetween. Therefore, when the water level drops, the pumping start water level HWL at the impeller inlet level and the lowest water level (pumping cutoff water level) LW
When the water level reaches a predetermined level between L, the intake valve 12 is opened and air is sent to the inlet of the impeller 3 to switch from pumping operation to air operation. 3) When the condition reaches IWL, the intake valve 12 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 12 is performed based on a signal outputted from the pumping start water level IL or LWL to the intake valve 12 by detecting the pumping start water level IL or LWL using a water level gauge (not shown).

Next, a method for detecting the operating status of the indoor shaft pump 1, and
A method of supplying lubricating water to the bearings 5 and 8 will be explained.

In the operating state of the chamber shaft pump 1 in which the main shaft 2 is rotationally driven, if the water level in the water suction well 6 is equal to or higher than the pumping start water level HWL, the intake valve 12 of the intake pipe 13 is closed, and the impeller 3 Pumping operation is performed because water is sucked up. In this case, since the shaft power of the main shaft 2 is larger than that during air operation, the torsion of the transmission shaft 14 becomes large, and the relative positional deviation between the two detected parts 15 and 17 becomes large. Therefore, the wrap time S of the two detection signals a and b shown in FIG. 2 becomes small. This lap time S is detected by the detection circuit 19 in FIG. 1 and displayed on the display 33 via the comparison circuit 21, so that it can be known that the soybean cake pump 1 is in pumping operation.

Furthermore, since the shaft power of the main shaft 2 and the discharge amount have a certain relationship depending on the type of pump and installation conditions, by checking the characteristics of the pump in advance and inputting it to the comparison circuit 21, the The operating status of the pump can be known by converting the detection signal C into shaft power and discharge amount on the display 33 via the comparison circuit 21 and digitally displaying the converted information.

On the other hand, the comparison circuit 21 receiving the detection signal C from the detection circuit engineer 9 compares the lap time S with the first set value St from the setting device 22, and determines that the lap time S is lower than the first set value S1. When the shaft power is smaller than a predetermined value, that is, during pumping operation when the shaft power is larger than a predetermined value, a closing signal sh is output to the valve 9C, and the valve 9C is closed.
C is closed. In this case, the bearing 5.8 is lubricated and cooled by the self-lifted water sucked up by the impeller 3.

As the pumping operation continues, the water level will rise to the pumping start water level (IWL).
Even if the pumping cutoff water level drops below IJL, the intake valve 12 remains closed until the pumping cutoff water level drops to IJL.
Lubrication and cooling of the bearings 5 and 8 by self-pumped water continues.

When the water level drops to around the pumping cutoff water level LWL, the intake valve 1
2 is opened to send air to the inlet of the impeller 3, and the pumping operation is switched to the air operation. During this driving,
Since the torque of the main shaft 2 and the transmission shaft 14 becomes significantly small, the phases of the first and second detection signals a and b output from both detectors Ca and Cb become small (and the wrap time S in Fig. 2 becomes large). Become.

Here, the comparison circuit 21 in FIG. 1 compares the wrap time S of the wrap signal C from the detection circuit 19 with the second set value S2 from the setter 22, and determines that the wrap time is greater than the second set value S2. If it is also large, a valve opening signal Op is output to the valve 9C.

As a result, the valve 9C opens and lubricating water is supplied from the lubricating water supply system 9 to the bearings 5 and 8 of the pump main shaft 2, and the bearings 5 and 8 are lubricated and cooled to continue stable operation. I can do it.

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 5 and 8 are lubricated by the self-pumping water.

In this way, while the soybean cake pump 1 is operating in air, the bearing 5.8 is lubricated and cooled by the lubricating water supplied from the lubricating water supply source 9, so that the dry operation is continued for a long time during the advance standby operation. The ceramic bearing 5°8 can also be used in the soybean cake pump 1 that performs atmospheric control operation.

It goes without saying that the present invention is not limited to the soybean cake pump 1 described in the above embodiment, but can also be applied to other pumps that can be operated in air.

Further, in the above embodiment, the first and second discs 16, 1
First and second detected parts 15.1 each having a slit at 8.
7 is provided, however, the dual-wave detection portions 15 and 17 may be formed by a reflecting plate, or may be provided directly on the transmission shaft 14.

Further, in the above embodiment, both the detectors Ca and Cb are reflective type optical sensors, or both the detectors Ca and Cb may be transmissive type optical sensors.

Furthermore, in the above embodiment, the rain detection signals a and b in FIG.
Although the operating conditions are detected and the lubricating water is supplied based on the lap time S of the rain detection signals a and b, the detection may also be performed based on the phases φ of the rain detection signals a and b.

In addition, in the above embodiment, the lap time S was compared with the first set value Sl and the second set value S2 in FIG. 1, but 5I=5
It may be set to 2. Further, the configuration of the control device 1i20 is not limited to that of the above embodiment.

〔Effect of the invention〕

As described above, according to the first aspect of the invention, the torsion of the transmission shaft, which has a certain relationship with the shaft power and discharge amount of the pump, is detected, so the operating status of the pump can be accurately detected.

In addition, it is possible to tell from the twist of the transmission shaft whether the pump is in pumping operation or in air operation, so during pumping operation when the bearings can be lubricated by self-pumped water, the lubricating water supply system is closed, while self-pumping water is used to lubricate the bearings. During air operation when the bearings cannot be lubricated by pumped water, a lubricating water supply system is opened, and the lubricating water supplied from this system lubricates and cools the bearings.
Stable operation can be continued. Therefore, ceramic bearings can be used even in pumps that perform advance standby operation or air management operation, which were conventionally considered impossible, and can improve versatility.

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 the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of a bean cake pump to which the present invention is applied, and FIG. 2 is a characteristic diagram showing the relationship between the first and second detection signals and the lap signal. 1... Pump (bean cake pump), 2... Main shaft, 5.8
... bearing, 9 ... lubricating water supply system, 10 ... prime mover, 14 ... transmission shaft, 15 ... first detected part, 17.
- Second detected part, Ca...first detector, cb...second detector, a...first detection signal, b...second detection signal. Patent applicant Kuhota Co., Ltd.

Claims (2)

[Claims] (1) The transmission shaft that transmits the output of the prime mover to the pump has a
and first and second detectors, which are provided with a second detected part separated from each other in the axial direction of the transmission shaft, and which detect the first and second detected parts, respectively, and output first and second detection signals. A method for detecting the operating status of a pump, characterized in that the operating status of the pump is detected based on both of the detection signals. (2) The transmission shaft that transmits the output of the prime mover to the pump has a first
and first and second detectors, which are provided with a second detected part separated from each other in the axial direction of the transmission shaft, and which detect the first and second detected parts, respectively, and output first and second detection signals. A method for supplying lubricating water to a bearing of a pump, characterized in that the supply of lubricating water to the bearing of the main shaft of the pump is controlled to be stopped from the lubricating water supply system based on both of the detection signals.