JP2007327393A - Self-priming pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a self-priming pump capable of inexpensively and simply achieving pump performance requested by a customer without preparing multiple kinds of pumps each having distinct performance and without degrading self-priming capability of the pump. <P>SOLUTION: This self-priming pump is provided with: a rotatable main shaft 10; an impeller 12 mounted to the main shaft 10; and pump casings 16, 20 and 22. The discharge casing 20 includes: a main volute chamber 30 with the impeller 12 arranged therein and an auxiliary volute chamber 31; a gas-liquid separation chamber 32 for separating a gas from a fluid discharged from the impeller 12; and a communication chamber 34 guiding the fluid discharged through the auxiliary volute chamber 31 from the impeller 12 to the gas-liquid separation chamber 32. On the suction casing 16, a projecting part 42 partitioning a part between the auxiliary volute chamber 31 and the main volute chamber 30, and extending to the vicinity of a circumferential edge of the impeller 12 is formed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a self-priming water pump, and more particularly to a self-priming water pump capable of sucking and discharging air and then discharging water even when the suction pipe is full when the pump is started.

  2. Description of the Related Art Conventionally, a self-priming water pump that can suck up and discharge air and then discharge water even when the suction pipe is filled when the pump is started is known (for example, Patent Documents 1 to 3). reference). An example of such a self-priming water pump is shown in FIG.

  In the self-priming water pump shown in FIG. 1, as the impeller 112 rotates, the priming water for self-priming introduced into the pump casing before the pump is started, and the suction casing suction at the center of the impeller 112 Air in a suction pipe (not shown) connected to the mouth is agitated and mixed by the impeller 112, and the gas-liquid mixed water is discharged from the impeller 112 through the auxiliary vortex chamber 131 to the communication chamber 134. This gas-liquid mixed water is ejected so as to form a swirling flow in the gas-liquid separation chamber 132 through the communication passage 136, whereby water and air are separated in the gas-liquid separation chamber 132. The air separated from the water is discharged from the discharge port 118 to a discharge pipe (not shown), and the suction pipe is filled with water before the self-priming operation ends.

  Here, in the self-priming water pump shown in FIG. 1, the gap between the winding start portion 130 a of the main vortex chamber 130 that partitions the sub-vortex chamber 131 and the main vortex chamber 130 and the outer peripheral edge of the impeller 112 is the self-propelled water pump. A great influence on the absorption capacity. That is, if the gap between the winding start portion 130a of the main vortex chamber 130 that partitions the sub vortex chamber 131 and the main vortex chamber 130 and the outer peripheral edge of the impeller 112 is large, the gas-liquid mixing stirred and mixed by the impeller 112 is performed. Since a part of the water flows to the main vortex chamber 130 side, the gas-liquid mixed water discharged from the impeller 112 is not efficiently sent to the communication chamber 134, so that the self-priming ability of the pump decreases.

  In a general pump, performance such as the pump head and flow rate is adjusted by adjusting the outer diameter of the impeller. However, in the above-described self-priming water pump, if the outer diameter of the impeller 112 is reduced, the pump 112 Since the self-priming ability declines, this self-priming ability has to be sacrificed in order to achieve the performance required by the customer. On the other hand, in order to achieve the performance required by the customer without sacrificing the self-priming capacity, multiple types of pump casings suitable for the outer diameter of the impeller are prepared in advance, and the performance required by the customer Accordingly, it is necessary to select an appropriate type of pump, which increases manufacturing cost and labor.

Japanese Patent Laid-Open No. 50-21682 Japanese Patent Laid-Open No. 2002-217161 JP 2004-183561 A

  The present invention has been made in view of such problems of the prior art, and does not require many types of pumps having different performances, and does not reduce the self-priming ability of the pumps. It aims at providing the self-priming water pump which can implement | achieve the pump performance to carry out cheaply and simply.

  According to one aspect of the present invention, the pump performance required by the customer can be realized inexpensively and easily without preparing various types of pumps having different performances and without reducing the self-priming ability of the pump. A self-priming water pump is provided. The self-priming water pump includes a rotatable main shaft, an impeller attached to the main shaft, and at least two pump casings. The pump casing includes a main vortex chamber and a sub vortex chamber in which the impeller is disposed, a gas-liquid separation chamber for separating a gas from a fluid discharged from the impeller, and the sub vortex chamber from the impeller. And a communication chamber for guiding the fluid discharged through the gas-liquid separation chamber. One of the pump casings is provided with a convex portion that partitions the sub vortex chamber and the main vortex chamber and extends to the vicinity of the outer peripheral edge of the impeller.

  According to the self-priming water pump according to the present invention, one of the pump casings has a convex portion that extends to the vicinity of the outer peripheral edge of the impeller continuously with the start of winding of the main vortex chamber partitioning the auxiliary vortex chamber and the main vortex chamber. Therefore, even when the outer diameter of the impeller is reduced in order to meet the performance required by the customer, the fluid discharged from the impeller can be efficiently sent to the communication chamber. Therefore, the pump performance requested by the customer can be realized easily and inexpensively without preparing various types of pumps having different performances and without reducing the self-priming ability of the pump.

  Hereinafter, embodiments of a self-priming water pump according to the present invention will be described in detail with reference to FIGS. 2 to 8, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 2 is a longitudinal sectional view showing the self-priming water pump in the first embodiment of the present invention. As shown in FIG. 2, the self-priming water pump includes a rotatable main shaft 10, an impeller 12 attached to an end of the main shaft 10, a suction casing 16 having a suction port 14, and a discharge casing having a discharge port 18. 20 and a cover casing 22 arranged on the opposite side of the suction casing 16 with respect to the discharge casing 20. A suction pipe (not shown) is connected to the suction port 14 of the suction casing 16, and a discharge pipe (not shown) is connected to the discharge port 18 of the discharge casing 20.

  The main shaft 10 is supported by a bearing 24, and the bearing 24 is accommodated in a bearing body 26 attached to the cover casing 22. By driving a motor (not shown), the main shaft 10 rotates, and the impeller 12 rotates integrally with the main shaft 10. In addition, you may form each component of pumps, such as the suction casing 16, the cover casing 22, and the discharge casing 20, with polydicyclopentadiene.

  3 is a cross-sectional view taken along line III-III in FIG. 2, and FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. As shown in FIG. 3, around the impeller 12, a main spiral chamber 30 and a sub spiral chamber 31 whose cross-sectional area gradually increases along the rotation direction of the impeller 12 are formed. A gas-liquid separation chamber 32 for separating gas (air) from the fluid discharged from the impeller 12 is formed on the downstream side of the volute of the main spiral chamber 30. The discharge port 18 is located on the downstream side of the gas-liquid separation chamber 32.

  The discharge casing 20 is formed with a communication chamber 34 that guides the fluid discharged from the impeller 12 through the auxiliary spiral chamber 31 to the gas-liquid separation chamber 32. As shown in FIG. 4, between the communication chamber 34 and the gas-liquid separation chamber 32, a communication passage for introducing fluid from the communication chamber 34 along the wall surface of the gas-liquid separation chamber 32 in the cylindrical tangential direction. 36 is provided.

  In the self-priming water pump having such a configuration, when the motor is started, the impeller 12 attached to the main shaft 10 rotates. As the impeller 12 rotates, the suction casing 16 at the center of the impeller 12 is rotated. Air in a suction pipe (not shown) connected to the suction port 14 is agitated and mixed by the impeller 12 with priming water for self-suction introduced into the pump casing before the pump is started.

  The gas-liquid mixed water is discharged from the impeller 12 to the communication chamber 34, and this gas-liquid mixed water is jetted into the gas-liquid separation chamber 32 through the communication passage 36. At this time, since the gas-liquid mixed water is ejected in the tangential direction of the gas-liquid separation chamber 32, a swirling flow is generated inside the gas-liquid separation chamber 32. Due to the difference in specific gravity between water and air in the gas-liquid mixed water, a difference occurs in the centrifugal force acting on them, so that the water swirls along the outer peripheral wall surface of the gas-liquid separation chamber 32 and the air is in the gas-liquid separation chamber 32. Gather on the center side of. For this reason, air is separated from water, and an inverted conical air layer 38 is formed on the center side of the gas-liquid separation chamber 32.

  The air thus separated from the water is discharged from the discharge port 18 to the discharge pipe, and the water forming the swirling flow is returned to the main spiral chamber 30 from below the gas-liquid separation chamber 32. The air layer 38 formed in the gas-liquid separation chamber 32 gradually extends downward, but since the stopper 40 is provided at the lower part of the gas-liquid separation chamber 32, the air layer is disposed below the stopper 40. 38 will not grow.

  As described above, the air in the suction pipe is gradually discharged to the discharge pipe, and eventually the entire suction pipe is filled with water. As a result, the self-priming operation is completed, and then the normal pumping operation is performed. In this pumping operation, water discharged from the impeller 12 is discharged from the spiral chamber 30 mainly through the gas-liquid separation chamber 32 to the discharge pipe.

  When the operation of the pump is stopped, the water in the discharge pipe and the water in the pump casing flow backward to the suction pipe side, but a part of them remains in the pump casing and functions the same as the above-described priming water before starting the pump.

  Here, as shown in FIG. 3, in the self-priming water pump in the present embodiment, the convex portion 42 provided in the suction casing 16 is positioned between the outer peripheral edge of the impeller 12 and the communication chamber 34. ing. The convex portion 42 extends to the vicinity of the outer peripheral edge of the impeller 12 according to the outer diameter of the impeller 12. The inner peripheral edge of the convex portion 42 and the outer peripheral edge of the impeller 12 are concentric, and a narrow gap is formed between them. Further, the convex portion 42 in the present embodiment extends in a predetermined angle range around the main shaft 10 along the outer periphery of the impeller 12. The convex portion 42 may be molded to a size corresponding to the outer diameter of the impeller 12 each time, or a convex portion having a size corresponding to the outer diameter of the impeller 12 may be used as a casing. A plurality of types may be prepared as separate bodies.

  5 is an enlarged sectional view of the vicinity of the convex portion 42, FIG. 6 is a front view showing the suction casing 16, and FIG. 7 is a sectional view taken along the line VII-VII in FIG. As described above, the convex portion 42 provided in the suction casing 16 is disposed so as to partition the sub vortex chamber 31 and the main vortex chamber 30 and extends to the vicinity of the outer peripheral edge of the impeller 12. Thereby, even if it is a case where the outer diameter of the impeller 12 is made small in order to adapt to the performance requested by the customer, the fluid discharged from the impeller 12 can be efficiently sent to the communication chamber 34. Therefore, the self-priming ability of the pump can be maintained only by arranging the convex portion 42 corresponding to the outer diameter of the impeller 12. Thus, according to the self-priming water pump of this embodiment, the pump performance required by the customer is inexpensive without preparing various types of pumps having different performances and without reducing the self-priming ability of the pump. And it can be realized easily.

  Here, as shown in FIG. 3, the convex portion 42 of the suction casing 16 described above preferably extends along the outer periphery of the impeller 12 in an angle range of a maximum of 35 ° centering on the main shaft 10. The gap between the outer peripheral edge of the impeller 12 and the convex portion 42 is preferably at most 15% of the outer diameter of the impeller 12. The convex portion 42 may have any shape as long as it extends the communication chamber 34 to the vicinity of the outer peripheral edge of the impeller 12. For example, as in the convex portion 42 a shown in FIG. It does not have to extend in the direction. Moreover, although this embodiment demonstrated the example which provided the convex part in the suction casing 16, it is not restricted to this. For example, a convex portion may be provided on the cover casing 22. Further, in the present embodiment, the cyclone type self-priming water pump that separates air and water by generating a swirling flow in the gas-liquid separation chamber 32 has been described. However, the present invention is not limited to the cyclone type self-priming water pump. It can be applied to a self-priming water pump of the type.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and it goes without saying that the present invention may be implemented in various forms within the scope of the technical idea.

It is a longitudinal cross-sectional view which shows an example of the conventional self-priming water pump. It is a longitudinal cross-sectional view which shows the self-priming water pump in the 1st Embodiment of this invention. It is the III-III sectional view taken on the line of FIG. It is the IV-IV sectional view taken on the line of FIG. It is an expanded sectional view of the convex part vicinity shown in FIG. It is a front view which shows the suction casing of FIG. It is the VII-VII sectional view taken on the line of FIG. It is a front view which shows the modification of the convex part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Main axis | shaft 12 Impeller 14 Suction port 16 Suction casing 18 Discharge port 20 Discharge casing 22 Cover casing 24 Bearing 26 Bearing fuselage 30 Main vortex chamber 31 Subvortex chamber 32 Gas-liquid separation chamber 34 Communication chamber 36 Communication passage 38 Air layer 40 Stopper 42 Convex

Claims (3)

A rotatable main shaft, an impeller attached to the main shaft, a main vortex chamber and a sub-vortex chamber in which the impeller is disposed, and a gas-liquid separation for separating gas from the fluid discharged from the impeller A self-priming water pump comprising: a chamber; and at least two pump casings having a communication chamber for guiding fluid discharged from the impeller through the auxiliary vortex chamber to the gas-liquid separation chamber,
One of the at least two pump casings is formed with a convex portion that partitions the sub vortex chamber and the main vortex chamber and extends to the vicinity of the outer peripheral edge of the impeller. Water absorption pump.   2. The self-priming water pump according to claim 1, wherein the convex portion extends in a predetermined angle range centering on the main shaft along the outer periphery of the impeller.   The self-priming water pump according to claim 1 or 2, wherein at least one of the pump casings is made of polydicyclopentadiene.

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