JPH0792076B2 - Lubrication water supply method for bearings of engine driven pump - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for supplying lubricating water to a bearing of an engine driven pump.

[Prior Art] For example, as a bearing of a vertical shaft pump, a ceramic bearing that is lubricated and cooled by self-pumping water and can continue stable operation is adopted.

In this type of bearing, the dry operation is performed for a very short time immediately after the pump is started, and after this short time, it is immediately lubricated and cooled by the self-lifting water to start the stable operation. That is, in the ceramic bearing, the dry operation is limited to a short time.

On the other hand, with the rapid progress of urbanization, the inflow of rainwater to pumping stations installed in waterways is becoming large and rapid. In such a situation, even if the water level of the suction well at the drainage pump station drops below the pumping cutoff water level of the vertical shaft pump, the dry operation is continued, and the pre-standby operation and the air management operation that precede the operation state of the pump are performed. It is handled by doing.

In the vertical shaft pump used for the preceding standby operation and the air management operation, the dry operation is continued for a long time, and the lubricating water is not supplied to the bearing during this time. Therefore, it has not been possible to employ a ceramic bearing whose dry operation time is limited to a short time in a vertical shaft pump that performs a preceding standby operation and an air management operation.

As a means for solving such a problem, it is possible to supply lubricating water from the outside to the bearing, but in this case, it is not possible to continue supplying the lubricating water from the outside even during pumping operation. It is meaningless. Therefore, by measuring the water level of the intake well, if the water level drops to a preset water level, that is, lower than the pumping start water level of the vertical shaft pump, the method of supplying lubricating water to the bearing is adopted. It had been.

[Problems to be Solved by the Invention] However, in the method of supplying the lubricating water to the bearing based on the water level of the suction well as described above, a case where the water surface of the suction well is calm and a case where the water surface is wavy are considered. It is necessary to set the supply level of the lubricating water to a high level with a margin in consideration of the case where it is usually wavy.

However, according to such a control method, when the water surface is relatively calm, the lubricating water is supplied even during the pumping operation. That is, the useless supply of lubricating water was continued for a long time, and it was not possible to prevent useless injection of water to the bearing.

The present invention has been made in view of the above circumstances, and has been made by paying attention to the fact that in an engine-driven pump, the exhaust temperature of the engine also changes due to changes in the engine load during pumping operation and air operation. It is possible to use ceramic bearings even for pumps that continue dry operation for a long time, such as preceding standby operation and air management operation.
An object of the present invention is to provide a method of supplying lubricating water to a bearing of an engine-driven pump that can reliably and efficiently control the supply of lubricating water to the bearing to a minimum necessary amount.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a temperature sensor in an exhaust system of an engine, detects an exhaust temperature that fluctuates according to the load of the engine by the temperature sensor, and When the exhaust temperature reaches the set upper limit value due to the engine being operated under a high load by the pumping operation described above, the lubricating water supply system is closed, the supply of lubricating water to the bearing is stopped, and The lubricating water supply system is closed to supply the lubricating water to the bearing when the exhaust temperature is lowered to the set lower limit value by the operation of the engine under a low load.

[Operation] According to the present invention, when the exhaust temperature rises due to the engine being operated under a high load by the pumping operation of the pump, this rise in exhaust temperature is detected by the temperature sensor provided in the exhaust system of the engine. , When the exhaust temperature reaches the upper limit preset by the characteristics of the engine,
Stop the supply of lubricating water from the lubricating water supply system to the bearings of the pump main shaft.

Further, when the engine is operated at a low load due to the air operation of the pump and the exhaust temperature is lower than that during the pumping operation, the decrease in the exhaust temperature is detected by the temperature sensor, and the exhaust temperature depends on the engine characteristics. When the preset lower limit value is reached, lubricating water is supplied from the lubricating water supply system to the bearing of the pump main shaft.

As described above, since the lubricating water is supplied to the bearings for lubrication and cooling during the air operation of the pump, even for the pump performing the preparatory standby operation in which the dry operation is continued for a long time or the air management operation. In addition, a ceramic bearing can be adopted, and the supply of lubricating water to the bearing can be suppressed to a necessary minimum for efficient lubrication.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an engine-driven vertical shaft pump to which the present invention is applied. In the drawing, the main shaft 2 of the vertical pump 1 is a bearing 5 fixed to the base of a guide vane 4 on the upper side of an impeller 3 and a floor of an intake well 6. The bearing 8 is rotatably supported by a bearing 8 fixed at substantially the same height level as the surface 7, and is rotationally driven by, for example, a diesel engine E.

The bearings 5 and 8 are each made of ceramics such as silicon carbide, and lubricating water for lubricating and cooling is supplied to each from a lubricating water supply system 9.

The lubricating water supply system 9 includes a lubricating water supply source 9A and this lubricating water supply source
It is composed of a pipe line 9B for communicating 9A with the bearings 5 and 8, and a valve 9C such as an electromagnetic valve or an electric ball valve provided in the pipe line 9B. Therefore, when the valve 9C is opened, the lubricating water supply source 9A supplies the lubricating water to the bearings 5 and 8, and when the valve 9C is closed, the supply of the lubricating water to the bearings 5 and 8 is stopped.

The exhaust system EX of the engine E is provided with a temperature sensor 10 for detecting the exhaust temperature. The temperature sensor 10 is provided at the inlet of the exhaust pipe P in the exhaust system EX, that is, at a position immediately downstream of the exhaust passage of the engine E, and a signal is output from the temperature sensor 10 to the control means 11 from which the lubricating water supply system is provided. 9 valve 9C
A signal is output to the valve 9C to control the opening and closing of the valve 9C.

Further, in this vertical pump 1, the impeller 3 is disposed above the lowest water level LWL peculiar to the pump that sucks air when the depth of the suction port is less than this, and at the lower side of the inlet of the impeller 3, that is, the blade. An intake pipe 13 is provided which is opened in the passenger compartment and has an air / water switching intake valve 12 interposed in the middle thereof.
Therefore, when the water level falls, when the water level reaches a predetermined level between the pumping start water level HWL at the impeller inlet level and the minimum water level (pumping cutoff water level) LWL, the intake valve 12 is opened to send air to the inlet of the impeller 3. The pumping operation is switched from the pumping operation to the air operation, and when the water level rises, the water level of the suction well is at the inlet level HW of the impeller 3.
When it becomes L, the intake valve 12 is closed, and while the residual air is being sucked, the air operation is switched to the pumping operation.

The intake valve 12 is opened and closed based on a signal output to the intake valve 12 from the pumping start water level HWL or LWL detected by a water level gauge (not shown).

Next, a procedure for supplying lubricating water to the bearings 5 and 8 will be described.

In the operating state of the vertical shaft pump 1 in which the main shaft 2 is rotationally driven, if the water level of the 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 causes water to flow. Is pumped up and pumped up. In this case, the bearings 5 and 8 are lubricated and cooled by the self-lifted water sucked up by the impeller 3.

By continuing the pumping operation, even if the water level falls below the pumping start water level HWL, the closed state of the intake valve 12 is maintained until the pumping cutoff water level LWL falls, and the bearing 5 by self-pumping, 8 Lubrication and cooling continue.

Exhaust temperature rises because the engine E is operated under a high load in the pumping operation described above. This rise in exhaust temperature is detected by the temperature sensor 10 provided at the inlet of the exhaust pipe P in the exhaust system EX of the engine E, and outputs this detection signal to the control means 11, where the exhaust temperature is the characteristic of the engine E. Judgment is made when it reaches the upper limit value (for example, about 450 ℃ for 210hp engine, about 220 ℃ for 90hp engine, about 210 ℃ for 80hp engine) preset by Then, a control signal is output to the valve 9C, the valve 9C is closed, and the supply of lubricating water from the lubricating water supply system 9 to the bearings 5 and 8 of the pump main shaft 2 is stopped.

When the water level drops near the pumping cutoff water level LWL, the intake valve 12 is opened to send air to the inlet of the impeller 3 to switch the pumping operation to the air operation.

When the engine E is operated at a low load by the air operation, the exhaust gas temperature decreases. This decrease in the exhaust temperature is detected by the temperature sensor 10 provided at the inlet of the exhaust pipe P in the exhaust system EX of the engine E, and this detection signal is output to the control means 11, where the exhaust temperature is the characteristic of the engine E. The lower limit preset by (for example, about 260 ℃ for 210 horsepower engine, about 1 for 90 horsepower engine)
When the temperature reaches 00 ° C, approximately 95 ° C in the case of an 80 horsepower engine), it judges this and outputs a control signal to the valve 9C, and opens the valve 9C to make the bearing of the pump main shaft 2 from the lubricating water supply system 9 Lubricating water is supplied to the bearings 5 and 8 to lubricate and cool the bearings 5 and 8. Therefore, even if the vertical pump 1 is switched to the air operation and the bearings 5 and 8 are no longer lubricated by the self-pumping water, the lubricating water supplied from the lubricating water supply system 9 is used after an extremely short time (2 to 3 minutes). It is lubricated and stable operation can be continued.

By continuing the air operation, the water level of the intake well 6 rises,
When the pumping start water level HWL is reached, pumping operation is switched as described above, and the bearings 5 and 8 are lubricated by the pumping.

As described above, since the bearings 5 and 8 are lubricated and cooled by the lubricating water supplied from the lubricating water supply system 9 during the air operation of the vertical shaft pump 1, the preparatory standby operation in which the dry operation is continued for a long time is performed. Also for the vertical pump 1 that performs air management operation,
Ceramic bearings 5 and 8 can be used, and
Since the lubricating water is supplied only when the vertical pump is operating in the air, the amount of the lubricating water supplied to the bearing can be suppressed to the necessary minimum.

Needless to say, the present invention can be applied not only to the vertical shaft pump 1 described in the above embodiment, but also to other pumps that can perform air operation.

[Effects of the Invention] As described above, according to the present invention, the fluctuation of the exhaust temperature of the engine due to the fluctuation of the engine load during the pumping operation and the air operation is detected by the temperature sensor, and the bearing is automatically pumped. During high load operation of a lubricable engine, the lubricating water supply system is closed, and the exhaust temperature is detected during low load operation in which the bearing cannot be lubricated by self-lifting by switching to air operation. The lubrication water supply system is opened by the signal from the temperature sensor, and the lubrication water supplied from this can lubricate and cool the bearings to continue stable operation. Ceramic bearings can also be used for pumps that perform stand-by operation and air management operation, which improves versatility.

In addition, since the amount of lubricating water supplied to the bearing can be suppressed to a necessary minimum, it is possible to save the lubricating water and the power for supplying the lubricating water.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a vertical shaft pump to which the present invention is applied. 1 …… Vertical pump 2 …… Spindle 3 …… Impeller 5,8 …… Ceramics bearing 9 …… Lubrication water supply system 9A …… Lubrication water supply source 9B …… Pipe line 9C …… Valve 10 …… Temperature sensor E …… Engine EX …… Engine exhaust system

Claims (1)

[Claims] 1. When the water level rises, the residual air is sucked up from the impeller inlet when the water level is equal to or higher than the pumping start water level at the inlet level of the impeller to switch from air operation to pumping operation, and when the water level falls, the impeller inlet level. Ceramics supporting the main shaft of an engine-driven pump configured to send air to the impeller inlet at a predetermined water level between the pumping start water level and the pumping cutoff water level to switch from pumping operation to air operation A method for supplying lubricating water to a bearing by means of a lubricating water supply system interposed between a lubricating water supply source and a pipe line communicating the bearing, wherein a temperature sensor is provided in an exhaust system of the engine. It detects that the exhaust temperature fluctuates according to the load of the engine and the engine is operated under high load by pumping water, and the exhaust temperature reaches the set upper limit value. And closing the lubricant supplying system, stopping the supply of the lubricating water with respect to the bearing, and, by the engine is low load operation by the gas during operation of the pump,
A lubricating water supply method for a bearing of an engine driven pump, wherein the lubricating water supply system is opened to supply the lubricating water to the bearing when the exhaust gas temperature falls to a set lower limit value.