JPH11247798A - Centrifugal volute pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a centrifugal volute pump whose energy loss is reduced and pumping efficiency is improved by suppressing contraflow of liquid from a volute chamber to a center portion of an impeller, which liquid is provided with energy by the impeller. SOLUTION: A pump part 10B of a centrifugal volute pump is composed of an arcuate pump chamber 30 made up of an arcuate casing 34, and a volute pump chamber 43 made up of a volute casing 36. A volute starting position A of the volute casing 36 is so set as to obtain a volute angle θ of the volute pump chamber 32 not less than 80 degrees and less than 360 degrees. A flow amount of liquid returned to the center portion of an impeller 24 can be reduced, which liquid is one fed from the arcuate pump chamber 30 between the blades of the impeller 24 to the volute pump chamber 32. Pumpling efficiency of the centrifugal volute pump, that is the pump part 10B, can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal centrifugal pump, and more particularly to a centrifugal centrifugal pump suitable for use as a washer pump for discharging a window washer fluid or a headlight washer fluid in a vehicle or the like.

[0002]

2. Description of the Related Art Centrifugal centrifugal pumps are used in various fields. For example, centrifugal centrifugal pumps are widely used in vehicles and the like as washer pumps for discharging window washer fluid and headlight washer fluid.

[0003] In this type of centrifugal centrifugal pump, an impeller is rotatably housed in a casing (volute casing). This casing is formed in a spiral shape as a whole, and starts to be wound from a cut-off portion provided close to the tip of the impeller (in other words, the end of the casing is set as a volute winding start position).
It is formed spirally and continuously along the periphery of the impeller to the discharge port. Thus, a spiral spiral chamber is provided sequentially and continuously along the periphery of the impeller (for example, see Japanese Patent Application Laid-Open No. 8-261195).

In this centrifugal centrifugal pump, energy (centrifugal force) can be given to the liquid by rotating the impeller in the casing. For example, the liquid flowing from an inflow port provided at a central portion of the impeller is impeller. The liquid can be sequentially sent out to the discharge port through a spiral chamber provided along the outer periphery of the liquid, and the liquid can be discharged from the discharge port.

However, there is a gap between the upper and lower peripheral edges of the impeller and the casing, and there is also a gap between the impeller blades. It is conceivable that a flow of a part of the liquid flowing through the spiral chamber returns to the center direction of the impeller through the gap due to the difference in the flow rate discharged from the impeller. If a part of the liquid sent from the impeller to the swirl chamber has a flow returning toward the center of the impeller, the returning flow does extra work for sending the liquid to the discharge port. Energy loss. In particular, the energy loss was remarkable in a low flow rate high head pump having a comparative rotation speed (specific speed) Ns of about 80, such as a washer pump of a vehicle.

[0006] Therefore, the flow returning to the center of the impeller despite being sent out to the spiral chamber is a large negative factor that lowers the pump efficiency, and there has been a long-awaited measure to prevent this. .

In this case, by reducing the length of the spiral flow path in the spiral pump (in other words, by reducing the outer diameter of the impeller), the flow rate of the liquid flowing from between the impeller blades to the spiral flow path (the impeller) It is also conceivable to adjust the amount of flow returning toward the center of the image. However, since there is a correlation between the outer diameter of the impeller and the pump discharge pressure, simply reducing the outer diameter of the impeller in this manner may lower the pump discharge pressure and make it impossible to obtain the required pressure.

[0008]

SUMMARY OF THE INVENTION In consideration of the above facts, the present invention makes it difficult for the liquid energized by the impeller to flow back from the spiral chamber toward the center of the impeller.
An object of the present invention is to provide a centrifugal centrifugal pump in which energy loss can be reduced and pump efficiency can be increased, and which can be realized with a simple structure without increasing the number of parts and easy to manufacture and at low cost. It is.

[0009]

According to a first aspect of the present invention, there is provided a centrifugal centrifugal pump in which a liquid is discharged from a discharge port by rotation of an impeller, wherein the circular casing is formed concentrically with the impeller. An arc pump chamber, and a spirally provided from the arc pump chamber to the discharge port on the downstream side in the impeller rotation direction of the arc pump chamber in a spiral manner, downstream of the arc pump chamber in the impeller rotation direction. Pump chamber constituted by a volute casing having a circumferential end on the side set as a volute winding start position and a circumferential end on the upstream side in the impeller rotation direction of the arc pump chamber set as a volute winding end position. And characterized in that:

In the centrifugal centrifugal pump according to the first aspect, an arc pump chamber formed by an arc casing, a centrifugal pump chamber formed by a volute casing,
It has. That is, this centrifugal centrifugal pump has a configuration in which the volute winding start position of the volute casing is set to be shifted by a predetermined range to the discharge port side as compared with the conventional centrifugal pump.

When the impeller rotates, the liquid is energized by the impeller in the arc pump chamber to be boosted in pressure, and then flows into the spiral pump chamber with the rotation of the impeller, is accelerated, and is discharged from the discharge port.

Here, the arc pump chamber of the centrifugal centrifugal pump is a region where the energy (action of centrifugal force) given to the liquid from the impeller is small. Therefore, the arc pump chamber is set in accordance with the set range of the arc pump chamber. The flow rate flowing from the arc pump chamber (between the impeller blades) to the centrifugal pump chamber is adjusted to reduce the flow rate of a part of the liquid sent out from the arc pump chamber (between the impeller blades) to the centrifugal pump chamber. be able to. This improves pump efficiency.

On the other hand, if the volute winding start position of the volute casing is too close to the discharge port (if the winding angle from the volute winding start position of the volute pump chamber to the volute winding end position is too small). Since the liquid (energy of centrifugal force) given from the impeller in the arc pump chamber flows into the spiral pump chamber at a stretch, the flow velocity of the liquid flowing into the spiral pump chamber becomes too fast, and the liquid near the discharge port becomes too high. The difference with the flow velocity becomes large and a vortex is generated, so that the pump efficiency is reduced. Therefore, it is necessary to set the winding angle of the spiral pump chamber so that the difference between the flow rate of the liquid near the discharge port and the flow rate in the spiral pump chamber becomes small.

That is, in this centrifugal centrifugal pump, by appropriately setting the range between the arc pump chamber and the centrifugal pump chamber (in other words, the winding angle of the centrifugal pump chamber, ie, the volute winding start position), the vicinity of the discharge port is improved. In the range where the difference between the liquid flow rate and the flow rate in the centrifugal pump chamber is small,
In the arc pump chamber, the maximum pressure can be given by applying the maximum energy to the liquid from the impeller, and the liquid can be delivered with the maximum pump efficiency.

Further, since it has a simple structure including an arc pump chamber (arc casing) and a spiral pump chamber (volute casing) and has a simple shape itself, it is easy to manufacture and low in cost, and the number of parts is small. Does not increase.

As described above, in the centrifugal centrifugal centrifugal pump according to the first aspect, it is difficult for the liquid energized by the impeller to flow back from the centrifugal pump chamber toward the center of the impeller. This can be realized at a low cost with a simple structure, without an increase in the number of parts, and easy to manufacture.

A centrifugal centrifugal pump according to a second aspect of the present invention is the centrifugal centrifugal pump according to the first aspect, wherein a winding angle of the volute pump chamber from the volute winding start position to the volute winding end position is 80 degrees or more. , The volute winding start position of the volute casing is set to be less than 360 degrees.

In the centrifugal centrifugal pump according to the second aspect, since the winding angle of the centrifugal pump chamber (ie, the volute winding start position) is suitably set, the flow velocity of the liquid near the discharge port and the flow velocity in the centrifugal pump chamber are set as described above. The difference is reduced and the liquid can be pumped with maximum pump efficiency by maximizing the energy from the impeller to the liquid.

A centrifugal centrifugal pump according to a third aspect of the present invention is the centrifugal centrifugal pump according to the second aspect, wherein the winding angle is set to 115 degrees or more and less than 185 degrees.

In the centrifugal centrifugal pump according to the third aspect, the winding angle of the centrifugal pump chamber is more preferably set, so that the pump efficiency can be further increased.

[0021]

FIG. 1 is a longitudinal sectional view showing the entire structure of a centrifugal centrifugal pump 10 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the configuration of a main part of the centrifugal centrifugal pump 10.

The centrifugal centrifugal pump 10 is applied to, for example, a washer pump device for discharging a window washer fluid in a vehicle or the like.

This centrifugal centrifugal pump 10 has a motor unit 1
0A and the pump unit 10B are integrally provided. The housing 12 constituting the motor unit 10A and the pump unit 10B is formed of a resin and is formed in a substantially cylindrical shape, and a resin end housing 14 is fixed to one end opening of the housing 12 so that the inside is sealed. ing. A connector 16 is integrally formed at a substantially corner of the end housing 14 so as to be exposed to the outside. An external connector (not shown) is fitted into the connector section 16 and connected to an electric circuit section (not shown) of the vehicle.

An intermediate portion of the housing 12 opposite to the end housing 14 (that is, a boundary portion between the motor portion 10A and the pump portion 10B) is partitioned by a partition wall 18. The armature shaft 20 of the motor unit 10A is supported by the partition wall 18, and an armature (not shown) is accommodated in the housing 12.

On the other hand, the pump unit 1 of the centrifugal centrifugal pump 10
OB comprises a housing 12 as an arc casing and a volute casing, and a bottom wall 22, and the tip of the armature shaft 20 reaches. An impeller 24 having a plurality of blades formed in a radial direction is attached to a tip of the armature shaft 20 and rotates together with the armature shaft 20 in the pump unit 10B. Further, an inlet 26 and an outlet 28 formed in the housing 12 communicate with the pump unit 10B. That is, the pump unit 10B constitutes a centrifugal centrifugal pump (centrifugal pump), and can pump the liquid sucked from the inlet 26 from the outlet 28 by the rotation of the impeller 24.

Here, as shown in detail in FIG. 2, the pump section 10B in which the impeller 24 is housed is provided with an arc pump chamber 30.
And a spiral pump chamber 32. The arc pump chamber 30 is constituted by an arc casing portion 34 (part of the housing 12) formed concentrically with the impeller 24. On the other hand, the spiral pump chamber 32 is located downstream of the circular pump chamber 30 in the direction of rotation of the impeller (the direction of the arrow R in FIG. 2) and is provided continuously from the circular pump chamber 30 to the outlet 28, and has a spiral volute. The casing 36 is constituted by a part of the housing 12. The volute casing section 36 (the volute pump chamber 3)
In 2), the circumferential end of the arc pump chamber 30 on the downstream side in the impeller rotation direction is set as a volute winding start position A, and the circumferential end of the arc pump chamber 30 on the upstream side in the impeller rotation direction ends in volute winding. Position B is set.

Here, the winding angle θ from the volute winding start position A to the volute winding end position B of the volute pump chamber 32 is preferably not less than 80 degrees and less than 360 degrees. The volute winding start position A of the volute casing portion 36 is set so as to be as follows. More preferably, the winding angle θ of the centrifugal pump chamber 32 is preferably in a range from 115 degrees to less than 185 degrees. FIG. 2 shows an example in which the volute winding start position A of the volute casing section 36 is set so that the winding angle θ of the volute pump chamber 32 becomes 180 degrees.

The centrifugal centrifugal centrifugal pump 10 having the above-described structure is mounted via a grommet 40 to a washer tank 38 disposed immediately near a tire wheel house of a vehicle.

Next, the operation of the present embodiment will be described. In the centrifugal centrifugal pump 10 having the above configuration, the arc casing 3
4 and a volute pump chamber 32 formed by a volute casing 36.
Constitute a pump section 10B. That is, the centrifugal centrifugal pump 10 is different from the conventional centrifugal pump in the volute casing portion 36 (the centrifugal pump chamber 3).
The volute winding start position A in 2) is located at the outlet 28.
Is set so as to be shifted by a predetermined range to the side.

When the impeller 24 rotates in the pump section 10B, the liquid is energized by the impeller 24 in the arc pump chamber 30 to be pressurized.
With the rotation of 4, the gas flows into the spiral pump chamber 32, is accelerated, and is discharged from the outlet 28.

Here, the arc pump chamber 30 of the pump section 10B is a region where the energy (action of centrifugal force) given to the liquid from the impeller 24 is small.
Depending on the setting range of the arc pump chamber 30, the arc pump chamber 30
(Between the blades of the impeller 24), the flow rate flowing out to the spiral pump chamber 32 is adjusted, and the arc pump chamber 30 (the impeller 24) is adjusted.
A part of the liquid sent to the centrifugal pump chamber 32 from between the blades of the impeller 24 can be reduced in the amount of flow returning to the center direction of the impeller 24. Thereby, the pump efficiency of the centrifugal centrifugal pump 10 is improved.

On the other hand, the volute casing 36
If the volute winding start position A of the (spiral pump chamber 32) is too close to the outlet 28 (the winding angle θ of the volute pump chamber 32 is too small), the energy from the impeller 24 in the arc pump chamber 30 is increased. Since the liquid given (the effect of the centrifugal force) flows into the spiral pump chamber 32 at a stretch, the flow velocity of the liquid flowing into the spiral pump chamber 32 becomes too high, and the difference between the liquid flow velocity near the outlet 28 and Larger vortices will result and lower pump efficiency. Therefore, the winding angle θ of the spiral pump chamber 32 is set so that the difference between the liquid flow rate near the outlet 28 and the flow rate in the spiral pump chamber 32 becomes small.
Need to be set.

In this case, in the present embodiment, the volute winding start position A of the volute casing portion 36 is set so that the winding angle θ of the volute pump chamber 32 becomes 180 degrees.
Is set, the winding angle θ of the volute pump chamber 32 is in the range of 80 degrees or more and less than 360 degrees.
The above effects can be obtained.

FIG. 3 shows a state in which the volute winding start position A of the volute casing portion 36 is set so that the winding angle θ of the volute pump chamber 32 becomes 80 degrees. FIG. 4 shows a state in which the volute winding start position A of the volute casing portion 36 is set so that the winding angle θ of the volute pump chamber 32 becomes 360 degrees.

FIG. 5 also shows a spiral pump chamber 32.
Is shown in the graph. In FIG. 5, line X is 300 cc /
This is an example of a centrifugal pump with a capacity of 10 s, line Y being 4
It is an example of a centrifugal pump with a capacity of 00cc / 10s.

In FIG. 5, the mode in which the winding angle θ is 360 degrees is the same as the conventional general spiral pump. Therefore, the winding angle θ of the spiral pump chamber 32 exceeds the pump efficiency in the mode of this winding angle θ = 360 degrees.
It can be seen that the range is 80 degrees or more and less than 360 degrees. More preferably, it is found that the winding angle θ should be in the range of 115 degrees or more and less than 185 degrees. further,
As in the present embodiment, the winding angle θ of the volute pump chamber 32 is set to 1
It can be seen that the pump efficiency is the best if it is set to 80 degrees.

That is, the winding angle θ of the spiral pump chamber 32
(In other words, if the volute winding start position A of the volute casing portion 36 is set in the range between FIG. 3 and FIG. 4, the difference between the flow velocity of the liquid near the outlet 28 and the flow velocity in the volute pump chamber 32 as described above. It can be seen that the liquid can be delivered from the impeller 24 to the maximum energy with the maximum pump efficiency.

As described above, in the centrifugal centrifugal pump 10 according to the present embodiment, the arc pump chamber 30 and the centrifugal pump chamber 3
2 (in other words, the winding angle θ of the volute pump chamber 32,
That is, by appropriately setting the volute winding start position A), the difference between the flow velocity of the liquid near the outlet 28 and the flow velocity in the volute pump chamber 32 is small,
In the arc pump chamber 30, the impeller 24 can apply a maximum amount of energy to the liquid to increase the pressure, and can discharge the liquid with the maximum pump efficiency.

Further, since it has a simple structure composed of the arc pump chamber 30 (arc casing section 34) and the spiral pump chamber 32 (volute casing section 36) and has a simple shape itself, it is easy to manufacture and low cost. Therefore, the number of parts does not increase.

As described above, in the centrifugal centrifugal pump 10 according to the present embodiment, it is difficult for the liquid energized by the impeller 24 to return from the centrifugal pump chamber 32 toward the center of the impeller, resulting in energy loss. The pump efficiency can be reduced and the pump efficiency can be increased, and this can be realized at a low cost and with a simple structure without increasing the number of parts.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an entire configuration of a centrifugal centrifugal pump according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a pump section of the centrifugal centrifugal pump according to the embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a configuration of a pump unit of the centrifugal centrifugal pump according to the embodiment of the present invention and corresponding to FIG. 2 showing a limit state of a winding angle of the centrifugal pump chamber.

FIG. 4 is a cross-sectional view corresponding to FIG. 2, showing a configuration of a pump section of the centrifugal centrifugal pump according to the embodiment of the present invention and showing a limit state of a winding angle of the centrifugal pump chamber.

FIG. 5 is a diagram showing a correspondence relationship between a winding angle of a volute pump chamber and pump efficiency of the centrifugal volute pump according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Centrifugal centrifugal pump 10A Motor part 10B Pump part 12 Housing 24 Impeller 28 Outlet (discharge port) 30 Arc pump chamber 32 Centrifugal pump chamber 34 Arc casing section 36 Volute casing section A Volute winding start position θ Winding angle

Claims (3)

[Claims] 1. A centrifugal centrifugal pump that discharges a liquid from a discharge port by rotation of an impeller, wherein: an arc pump chamber formed by an arc casing formed concentrically with the impeller; and the impeller rotation of the arc pump chamber. Is provided continuously in a spiral form from the arc pump chamber to the discharge port on the downstream side in the direction, and the circumferential end of the arc pump chamber on the downstream side in the impeller rotation direction is set as a volute winding start position and A centrifugal centrifugal pump comprising: a centrifugal centrifugal pump configured by a volute casing in which a circumferential end of the circular arc pump chamber on the upstream side in the impeller rotation direction is set as a volute winding end position. 2. The volute winding start position of the volute casing is set so that a winding angle of the volute pump chamber from the volute winding start position to the volute winding end position is not less than 80 degrees and less than 360 degrees. The centrifugal centrifugal pump according to claim 1, wherein: 3. The centrifugal centrifugal centrifugal pump according to claim 2, wherein the winding angle is set to 115 degrees or more and less than 185 degrees.