JPH0758079B2 - Lubrication water supply method for bearings of diesel engine driven pump - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for supplying lubricating water to a bearing of a diesel 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.

In view of such circumstances, in the present invention, in the diesel engine driven pump, the fuel injection amount adjustment rack of the engine is moved by the governor due to the fluctuation of the engine load during the pumping operation and the air operation, and the rotation speed is changed. The diesel engine drive system is designed to keep the bearing within a predetermined range, and can reliably and minimally control the supply of lubricating water to the bearing. An object of the present invention is to provide a method for supplying lubricating water to a pump bearing.

[Means for Solving the Problems] In order to achieve the above object, the present invention detects, by a moving amount detecting unit, an amount of a fuel injection amount adjusting rack of a diesel engine that is moved by a governor when the engine load changes, When the detected amount of movement reaches the set upper limit value, the supply of lubricating water from the lubricating water supply system to the bearing of the pump spindle is stopped, and when the amount of movement decreases to the set lower limit value, the lubricating water supply system is operated Lubricating water is supplied to the bearing.

[Operation] According to the present invention, when the moving amount of the fuel injection amount adjusting rack reaches the set upper limit value due to the high load operation of the engine by the pumping operation of the pump, this moving amount is detected by the moving amount detecting means. Detects and stops the supply of lubricating water from the lubricating water supply system to the bearing 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 movement amount of the fuel injection amount adjustment lap reaches the set lower limit value, this movement amount is detected by the movement amount detection means and the lubricating water is supplied. Supply lubrication water from the system to the bearing of the pump main shaft.

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

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

As shown in FIG. 2, a well-known fuel injection pump P attached to the engine E is moved by a governor G when the load of the engine E is changed to adjust a fuel injection amount adjustment rack R. Is provided, and a non-contact type movement amount detecting means 10 configured by, for example, a differential transformer for detecting the movement amount of the fuel injection amount adjusting rack R is provided. Then, a signal is output from the movement amount detection means 10 to the control means 11, and a signal is output from this to the valve 9C of the lubricating water supply system 9 to control the opening / 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 drops, 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.

When the diesel engine E is operated under a high load in the pumping operation described above, the governor G of the fuel injection pump P moves the fuel injection amount adjusting rack R in the injection amount increasing direction, and the movement amount at this time is the movement amount detecting means 10 The detection signal is output to the control means 11, and when the fuel injection amount adjustment rack R reaches the upper limit value preset by the characteristics of the engine E, the valve 9C is judged to judge this. A control signal is output to the valve 9C to close the valve 9C to stop the supply of the lubricating water from the lubricating water supply system 9 to the bearings 5 and 8 of the pump main shaft 2.

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 due to the air operation, the governor G of the fuel injection pump P controls the injection amount adjustment rack R.
Moves in the injection amount reducing direction, and the moving amount at this time is detected by the moving amount detecting means 10, and the detection signal is controlled by the controlling means.
11. When the fuel injection amount adjustment rack R reaches a lower limit value preset by the characteristics of the engine E, it judges this and outputs a control signal to the valve 9C,
9C is opened to connect the lubricating water supply system 9 to the bearing 5 of the pump spindle 2.
Lubricating water is supplied to 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 self-pumping,
The lubrication water supplied from the lubrication water supply system 9 lubricates the lubrication water so that 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 adopted.

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.

Although a differential transformer is used as the movement amount detecting means 10 in the above embodiment, a photoelectric tube may be used for optical detection.

[Effects of the Invention] As described above, according to the present invention, the movement amount detection means detects the movement amount of the fuel injection amount adjustment rack due to the fluctuation of the diesel engine load during the pumping operation and the air operation, During high-load operation of a diesel engine that can lubricate bearings with self-pumping water, the lubrication water supply system is closed and can be switched to air operation. , The lubricating water supply system is opened by the signal from the movement amount detector,
Lubricating water supplied from here can lubricate and cool the bearings to maintain stable operation.Therefore, ceramics can be used for pumps that perform pre-standby operation or air management operation, which has been impossible in the past. It is possible to use bearings and improve 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, and FIG. 2 is a schematic explanatory diagram of components of a fuel injection pump. 1 ... Vertical pump 2 ... Spindle 5,8 ... Ceramic bearing 9 ... Lubrication water supply system 10 ... Moving amount detection means E ... Diesel engine G ... Governor P ... Fuel injection pump R ... Fuel injection Quantity adjustment rack

Claims (1)

[Claims] 1. In a diesel engine drive type pump, a moving amount detecting means detects an amount of a fuel injection amount adjusting rack of the engine which is moved by a governor when a load of the engine changes, and the detected moving amount is a set upper limit value. The lubricating water supply system stops supplying the lubricating water from the lubricating water supply system to the bearing of the pump main shaft, and the lubricating water supply system supplies the lubricating water to the bearing when the amount of movement decreases to a set lower limit value. A method for supplying lubricating water to a bearing of an engine-driven pump, comprising: