JPH0419393A - Method for detecting operation condition of pump and method for supplying lubricating water to bearing of pump - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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.

In this type of bearing, a trial operation is performed for a very short period of time immediately after the pump is started, and after this short period of time, 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 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. We are responding by doing this.

The indoor shaft pump used in 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.

One possible solution to this problem is 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.

[Problem to be solved by the invention]

However, in this method of supplying lubricating water to bearings based on the water level of the water absorption well, it is necessary to consider whether the water surface of the water absorption well is calm or undulating. It was necessary to set the lubricant water supply stop level to a high level with some margin in consideration of the case where the lubricating water supply is stopped.

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 prevent unnecessary water from being injected into the bearing.

The present invention was made in view of these circumstances, and focused 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 method for detecting the operating status of a pump that can accurately detect the operating status of the pump, and a method for detecting the operating status of a pump that can reliably supply lubricating water to the bearing while controlling it to the minimum necessary level. The purpose is to provide a lubricating water supply method.

[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 a first optical fiber that emits light toward the detected part;
receiving light from the first optical fiber that has detected the detected part;
a second optical fiber that emits the received light toward the second detected part; and a third optical fiber that receives the light from the second optical fiber that has detected the second detected part;
The operating status of the pump is detected based on the detection output from the optical fiber.

In a second invention, first and second detected parts are provided on a transmission shaft that transmits the output of the prime mover to the pump, and are spaced apart in the axial direction of the transmission shaft, and emit light toward the first detected part. a first optical fiber, a second optical fiber that receives light from the first optical fiber that has detected the first detected part, and emits the received light toward the second detected part; A third optical fiber that receives light from the second optical fiber detected by the detection unit is provided, and lubricating water is supplied from the lubricating water supply system to the bearing of the pump main shaft based on the detection output from the third optical fiber. It is designed to control.

[Effect]

According to the present invention, the transmission shaft that transmits the output of the prime mover to the pump twists more as the shaft power of the pump increases. There is a relative positional shift in the rotational direction, and the light reception time, which is the output of the third optical fiber, is shortened by the positional shift. On the other hand, the shaft power and discharge amount of the bomb have a certain relationship depending on the type of pump and installation conditions, so if you check the characteristics of the pump in advance, the pump will pump water based on the detected output from the third optical fiber of J8. It is possible to know the operating status such as whether or not the machine is in operation and the amount of discharge.

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 above detection output. .

〔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 has been applied. It is rotatably supported by a bearing 8 which is fixed at approximately the same height level as 7, 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, lubricating water is supplied from the lubricating water supply source 9A to the bearings 5.8, and when the valve 9C is closed, the supply of lubricating water to the bearings 5, 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 .

A tip of a first optical fiber 41 that emits light toward the first detected portion 15 faces the first detected portion 15 . Light from the light source 23 passes through the first optical fiber 41 .

A second optical fiber 42 is arranged on the opposite side of the first optical fiber 4I in the first detected part 15, and this second optical fiber 42 transmits light through the first detected part 15. , the first detected part 15 of upper J8 is detected.
The light from the optical fiber 41 is received.

The second optical fiber 42 has its other end facing the second detected portion 17 and emits the received light toward the second detected portion 17 . A third optical fiber 4 is provided on the opposite side of the second optical fiber 42 in the second detected portion 17.
3 is arranged, and this third optical fiber 43 receives the light from the second optical fiber 42 that has detected the second detected part 17 by transmitting the light through the second detected part 17.

The third optical fiber 43 is connected to the photoelectric converter 24. This photoelectric converter 24 is connected to the third optical fiber 43
It converts light, which is the detection output from the sensor, into an electrical signal C.

The second and third optical fibers 42 and 43 have a transmission axis 1
When the transmission shaft 14 is rotating with no load applied to the first and second detected parts 15, respectively.
．． 17 at the same time, and receive the light from the first optical fiber 41 for the same amount of time,
As shown by waveform a in FIG. 3, light is received during time TI. Therefore, the electric signal C from the photoelectric converter 24 in FIG. 1 also has a waveform a in FIG. 3.

When a load is applied to the transmission shaft 14, the transmission shaft 14 is twisted, so that the detected portions 15.17 of the first and second disks 16.18 are relatively distorted, as shown in FIG. Misaligned. Therefore, while the light reception time of the second optical fiber 42 which receives the light from the first optical fiber 41 is TI, the light of the second optical fiber 42 is slightly blocked by the second disc 18. The light reception time for receiving light from the third optical fiber 43 or the second optical fiber 42 is T2, which is shorter than Tl, as shown in the waveform of FIG. In other words, transmission shaft 1
4 is twisted, the phases of the two detected parts 15 and 17 are shifted by φ, so that the electric signal C from the photoelectric converter 24 in FIG.
2 is shorter than TI by φ.

The photoelectric converter 24 in FIG.
Output to 1.

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 light reception time T2 and the first set value S1.
When the light reception time T2 is smaller than the first set value S1, that is, during pumping operation when the transmission shaft 14 is twisted, a closing signal sh is output to close the valve 9C. On the other hand, the comparison circuit 21 compares the light reception time T2 and the second set value S2.
When the light reception time T2 is larger than the second set value S2, that is, during air operation when the transmission shaft 14 is not twisted, a valve opening signal Op is output to open the valve 9C. Note that the first set value S1 is smaller than the second set value S2.

The light source 23, photoelectric converter 24, comparison circuit 21, and setting device 22 are incorporated into one control device ff1E20. Further, the output of the electrical signal C from the photoelectric converter 24 is displayed on the display 33 via the comparison circuit 21.

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 j3 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) L
When the water level reaches a predetermined level between WL, 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. When the water level rises, the water level in the water intake well 6 reaches the impeller When the inlet level OWL of No. 3 is reached, the intake valve I2 is closed, and the air operation is switched from the air operation to the pumping operation while sucking up the residual air.

The opening/closing of the intake valve 12 is performed based on a signal output from the pumping start water level 1 (WL or LWL) detected by a water level gauge (not shown) and outputted from there to the intake valve 12.

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 of the water suction well 6 is equal to or higher than the pumping start water level 81, 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 I4 becomes large, and the relative positional deviation between the two detected parts 15 and 17 becomes large. Therefore, as shown in the waveform of FIG. 3, the light reception time T2 becomes short.

This light reception time T2 is converted into an electric signal C by the photoelectric converter 24 shown in FIG. What you can know is what you can do.

Furthermore, since the shaft power and discharge amount of the main shaft 2 are constant depending on the type of pump and installation conditions, the light receiving time T2
By examining the relationship between the power and the shaft power and the relationship between the shaft power and the discharge amount and storing them in a memory circuit (not shown), the electric signal C from the photoelectric converter 24 can be transmitted to the display 33.
By converting it into shaft power and discharge amount and displaying it digitally, you can know the operating status of the pump.

On the other hand, the comparison circuit 21 receiving the electric signal C from the photoelectric converter 24 compares the light reception time T2 with the first set value S1 from the setting device 22, and finds that the light reception time T2 is the first set value S1.
When the shaft power is smaller than the 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. In this case, the bearing 5.8 is lubricated and cooled by the self-lifted 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 12 remains closed until the water level drops to the pumping cutoff water level LWL, and the bearing 5. 8 lubrication and cooling 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 torques of the main shaft 2 and the transmission shaft 14 are significantly reduced, there is almost no phase in the dual-wave detection section 1517 in FIG. 2, and therefore the light reception time T2 in FIG. 3 becomes long.

Here, the comparison circuit 21 in FIG. 1 compares the light reception time T2 of the electric signal C from the photoelectric converter 24 with the second set value S2 from the setting device 22, and determines that the light reception time T2 is the second set value. S2
, that is, when the torsion of the transmission shaft 14 is small, a valve opening signal Op is output to the valve 9C. As a result, the valve 9C opens and the lubricating water supply system 9 is transferred to the pump main shaft 2.
Lubricating water is supplied to the bearings 5 and 8.
lubrication and cooling.

Therefore, the bean cake pump 1 is switched to air operation,
Even if the bearings 5 and 8 are no longer lubricated by self-pumped water, they are lubricated by the lubricating water supplied from the lubricating water supply system 9, and stable operation can be continued.

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, during the submerged operation of the soybean cake pump l, the bearing 5.8 is lubricated and cooled by the lubricating water supplied from the lubricating water supply source 9, so that the preliminary standby operation in which dry operation continues for a long time is possible. 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 l 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 disks 1618
The first and second detected portions 15.17 each include a slit.
However, the dual-wave detection section 15.17 is formed of a reflecting plate, and the reflected light is transmitted to the second and third optical fibers 42.43.
Alternatively, both wave detection sections 15 and 17 may be provided directly on the transmission shaft 14.

Furthermore, in the above embodiment, the light reception time T2 was compared with the first set value S1 and the second set value S2 in FIG.
It may be set to 2. Further, the configuration of the control device 20 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 drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a soybean meal pump to which the present invention is applied, FIG. 2 is an enlarged view of a detection portion, and FIG. 3 is a characteristic diagram showing the relationship between light reception time and electric signal. 1... Pump (bean cake pump), 2... Main shaft, 5.8
... Bearing, 9... Lubricating water supply system, lO... Prime mover, 14... Transmission shaft, 15... First detected part, 17...
... second detected part, 41 - first optical fiber, 42 - second optical fiber, 43 - third optical fiber.

Claims (2)

[Claims] (1) The transmission shaft that transmits the output of the prime mover to the pump has a
and a second detected part provided spaced apart in the axial direction of the transmission shaft, a first optical fiber that emits light toward the first detected part, and a first optical fiber that detects the first detected part. a second optical fiber that receives the light and emits the received light toward the second detected part; and a third optical fiber that receives the light from the second optical fiber that has detected the second detected part. A method for detecting the operating status of a pump, characterized in that the operating status of the pump is detected based on the detection output from the third optical fiber. (2) The transmission shaft that transmits the output of the prime mover to the pump has a first
and a second detected part provided spaced apart in the axial direction of the transmission shaft, a first optical fiber that emits light toward the first detected part, and a first optical fiber that detects the first detected part. a second optical fiber that receives the light and emits the received light toward the second detected part; and a third optical fiber that receives the light from the second optical fiber that has detected the second detected part. A method for supplying lubricating water to a bearing of a pump, characterized in that the supply of lubricating water from a lubricating water supply system to a bearing of a pump main shaft is controlled based on the detection output from the third optical fiber.