JP2012215101A - Pump and pump control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve pump efficiency by reducing unnecessary energy with a simple structure and a simple control.SOLUTION: The pump includes a rotary drive shaft 5 provided inside a pump casing 3 having a fluid suction opening on one end side and a fluid ejection opening on the other end side; an impeller 4 mounted on the rotary drive shaft 5 for sucking a fluid from the fluid suction opening; a guide vane 9 provided around the rotary drive shaft 5 for guiding the fluid sucked from fluid suction opening between the pump casing 3 and the rotary drive shaft 5 toward the fluid ejection opening side rather than the impeller 4 along the rotary drive shaft 5. The guide vane 9 is mounted freely rotatably around the rotary drive shaft 5. A braking device 11 is provided for braking the free rotation of the guide vane 9.

Description

In the present invention, a rotary drive shaft is provided inside a pump casing provided with a fluid suction port on one end side and a fluid discharge port on the other end side, and fluid is sucked into the rotary drive shaft from the fluid suction port. Install the impeller,
A guide vane for guiding the fluid sucked from the fluid suction port between the pump casing and the rotation drive shaft and closer to the fluid discharge port than the impeller along the rotation drive shaft; The present invention relates to a pump provided around a rotary drive shaft and a control method thereof.

Conventionally, the guide vanes are generally fixed to a pump casing, and the velocity energy of the flow generated by the rotation of the impeller is converted into pressure energy, and the swirling flow generated by the rotation of the impeller is driven to rotate. The flow direction is changed along the axis and guided toward the fluid discharge port to increase the pump efficiency of the pump.
However, when the valve on the fluid discharge port side is throttled and the discharge flow rate of the pump is reduced, the discharge pressure of the pump increases, the pump efficiency decreases, and the load on the rotary drive shaft of the pump increases. Drive energy is consumed unnecessarily.
Therefore, in order to suppress an increase in load on the rotary drive shaft of the pump and prevent unnecessary consumption of the rotary drive force of the pump, the guide blade is attached so that its inclination angle can be changed, and the pump efficiency Has been proposed (see, for example, Patent Document 1).

JP 58-193000 A

  Although the pump described above can change the inclination angle of the guide vanes to adjust the conversion rate to the pressure with respect to the suction flow rate, there is a problem that the pump structure and the control of the inclination angle of the guide vanes are complicated.

  Therefore, the object of the present invention is to solve the above problems and increase pump efficiency in a small flow rate range by reducing unnecessary energy when the pump discharge flow rate is reduced with a simple structure and simple control. It is in place to be able to.

  The first characteristic configuration of the pump of the present invention is that a fluid suction port is provided on one end side and a rotary drive shaft is provided inside a pump casing provided with a fluid discharge port on the other end side. An impeller that sucks fluid from the fluid suction port is attached, and the fluid sucked from the fluid suction port is disposed between the pump casing and the rotary drive shaft and closer to the fluid discharge port than the impeller. A guide vane for guiding along the rotation drive shaft is provided around the rotation drive shaft, and the guide vane is mounted so as to be free to rotate around the rotation drive shaft. There is a braking device for braking the vehicle.

According to the first characteristic configuration of the present invention, by attaching the guide vane around the rotation drive shaft so as to be free to rotate, the valve on the fluid discharge port side is throttled, and the pressure on the downstream side of the impeller is reduced. When the flow rate is increased or the flow rate is decreased, the guide blades are rotated to suppress the conversion of the velocity energy of the fluid into the pressure energy, and the swirling flow of the fluid generated by the rotation of the impeller is guided by the guide blades. The function of conversion in the direction along the rotational drive shaft by the rotation is reduced, and the free wheel rotates with the swirling flow. Therefore, the load necessary for driving the pump can be reduced.
In addition, when the valve on the fluid discharge port side is opened and it is required to increase the flow rate of the fluid supplied to the downstream side of the impeller or decrease the pressure, the idler of the guide vanes by the braking device is braked. In this case, the fluid taken in from the fluid suction port is converted into velocity energy by the braked guide vane, and is also converted by the guide vane into a flow in a direction along the rotation drive shaft, and a load necessary for driving the pump. It is possible to increase the flow rate and pressure of the fluid exiting from the fluid discharge port while suppressing an unnecessary increase in.
Therefore, a simple structure in which the guide vanes are mounted so as to be free to rotate and a braking device is provided can increase the efficiency of the pump and use energy efficiently.

  According to a second characteristic configuration of the present invention, there is provided discharge water status detection means for detecting the state of the fluid on the fluid discharge port side, and the braking operation by the braking device is performed based on the detection status by the discharge water status detection means. There is a control device for the pump to be adjusted.

According to the second characteristic configuration of the present invention, the control is performed so as to adjust the braking operation of the braking device by the control device based on the detection by the discharge water state detection means accompanying the change in the state of the fluid of the discharge water. It is possible to prevent the load necessary for driving the pump from changing greatly due to a change in the state of the fluid, and to improve the pump efficiency.
Therefore, the output of the drive device that drives and rotates the rotary drive shaft can be small, and the entire device can be made inexpensive.

  According to a third aspect of the present invention, there is provided a feature of the third pump operating method, wherein the state of the fluid on the fluid discharge port side is detected, and the braking operation by the braking device is adjusted as the state of the fluid changes. The driving force required for rotating the rotary drive shaft is reduced.

According to the third characteristic configuration of the present invention, even if the valve on the fluid discharge port side is throttled and the state of the fluid, that is, the water pressure increases or the flow rate decreases, the braking operation by the braking device can be reduced. The guide blades are easy to idle, and the fluid taken in from the fluid suction port by the driving rotation of the impeller decreases the conversion rate of the flow direction of the fluid by the guide blades and the conversion rate from the velocity energy to the pressure energy. The increase in the discharge pressure is suppressed, and the load necessary for driving the pump is reduced.
Therefore, even when the amount of water to be used is small, the increase in the discharge pressure is suppressed, and the driving force necessary for driving the pump can be small power, and the pump efficiency is improved.

It is the whole longitudinal cross-sectional view of a pump. It is a longitudinal cross-sectional view of the principal part. It is a longitudinal cross-sectional view of the principal part of another embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIGS. 1 and 2, a fluid pumping port 1 is formed at the lower end portion, and a cylindrical pump casing 3 is formed in the upper lateral side portion to form a fluid discharge port 2, and is arranged in the pump casing 3. A mixed flow impeller type impeller 4 for sucking fluid, a rotary drive shaft 5 that is rotatably attached to the lower end portion and linked to a motor M as a drive device at the upper end portion, and a rotary drive shaft 5 A discharge bowl 8 having a front end side bearing 6 attached to the lower portion is disposed as an operating portion on the lower side, and a bearing device 20 for rotatably supporting the rotary drive shaft 5 is provided at the upper end of the rotary drive shaft 5. On the side, a vertical shaft pump is configured by being provided between the drive device and the pump casing.

  The discharge bowl 8 constitutes a part of the pump casing 3, and the fluid sucked from the fluid suction port 1 between the pump casing 3 and the rotary drive shaft 5 and closer to the fluid discharge port 2 than the impeller 4. The guide blade 9 for converting the velocity energy into pressure energy is guided around the rotary drive shaft 5 and is rotatably mounted around the rotary drive shaft 5 via the bearing portion 10. A discharge bowl 15, a rib 16 connecting the wall surface forming the fluid flow path and the bearing 6, and a fixed-side discharge bowl 14 into which the rotary drive shaft 5 is rotatably inserted via the bearing 6.

  Between the rotation-side discharge bowl 15 and the fixed-side discharge bowl 14, a braking device 11 that brakes the idle rotation of the guide vanes 9 is provided. The fluid discharge port 2 is provided with discharge water status detection means 12 for detecting the water pressure, flow velocity or flow rate that is the state of the fluid on the fluid discharge port side. The detection status by the discharge water status detection means 12, that is, the fluid discharge port A pump control device 13 that adjusts the braking operation by the braking device 11 is provided in accordance with changes in water pressure, flow velocity, or flow rate, which is the state of the fluid on the side. Examples of the discharge water status detection means 12 include a water pressure meter, a current meter, and a flow meter.

The braking device 11 includes a sliding member provided in each of the fixed-side discharge bowl 14 and the rotation-side discharge bowl 15, and a sliding member driving unit that performs a pressing operation toward the sliding member by a signal from the control device. ing.
This sliding member driving portion loosens the pressure when the water pressure, which is the fluid state on the fluid outlet side, increases or the flow velocity or flow rate decreases, and finally the guide vanes 9 freely play with respect to the pump casing 3. And the pressure is increased when the water pressure, which is the state of the fluid on the fluid discharge port side, decreases, or the flow velocity or flow rate increases. ) Is controlled so as to stop with respect to the pump casing 3.

[Another embodiment]
Other embodiments will be described below.

<1> The impeller 4 is not limited to the mixed flow blade type, but may be an axial flow blade type.
<2> The pump may be a horizontal axis pump in which the rotary drive shaft 5 is installed in the horizontal direction in addition to the vertical pump in which the rotary drive shaft 5 is installed in the vertical direction.
<3> The braking device 11 may be a clutch that switches to a state in which a rotational resistance force that is gradually different is applied, in addition to a brake that continuously resistances the idle rotation of the guide vanes 9.
<4> The control device 13 does not necessarily have to be provided. In that case, the braking device may be manually operated for braking.
<5> The braking device 11 is provided between the fixed-side discharge bowl 14 and the rotary-side discharge bowl 15 on the inner sliding surface, as shown in FIG. It may be disposed between the rotary casing 15 and the pump casing 3 at the outer sliding surface, that is, at the outer peripheral portion of the guide vane 9.
<6> Although the fluid state has been described with respect to the water pressure, the flow velocity, and the flow rate, the shaft power of a pump obtained from a combination of these may be used as the fluid state. In other words, in addition to the pressure gauge, flow meter, and current meter, the discharge water status detection means includes a torque meter that measures the force applied to the shaft of the pump, a wattmeter, ammeter, and voltmeter that measures the energy consumption of the drive unit A fuel flow meter can also be used.

  In addition, as mentioned above, although the code | symbol was written in order to make contrast with drawing convenient, this invention is not limited to the structure of an accompanying drawing by this entry. In addition, it goes without saying that the present invention can be carried out in various modes without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Fluid suction port 2 Fluid discharge port 3 Pump casing 4 Impeller 5 Rotation drive shaft 9 Guide blade 11 Braking device 12 Discharge water condition detection means 13 Control device

Claims (3)

Provided with a fluid suction port on one end side and provided with a rotary drive shaft inside the pump casing provided with a fluid discharge port on the other end side, and attached an impeller for sucking fluid from the fluid suction port to the rotary drive shaft ,
A guide vane for guiding the fluid sucked from the fluid suction port between the pump casing and the rotation drive shaft and closer to the fluid discharge port than the impeller along the rotation drive shaft; A pump provided around a rotary drive shaft,
The guide blade is attached to the rotation drive shaft so as to be free to rotate,
A pump provided with a braking device for braking the idle rotation of the guide vanes. A discharge water condition detection means for detecting a fluid state on the fluid discharge port side is provided;
The pump according to claim 1, further comprising a pump control device that adjusts a braking operation by the braking device based on a detection state by the discharge water state detection means. The pump control method according to claim 1,
Detecting the fluid state on the fluid outlet side,
A pump control method for adjusting a braking operation by the braking device to reduce a driving force necessary for the rotation of the rotary drive shaft as the state of the fluid changes.

Images