JP2008050958A - Self-priming pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a self-priming pump capable of stably discharging fluid to be transferred even if the fluid is brought into a gas-liquid mixed state. <P>SOLUTION: A liner ring 50 which rubbing-contacts with an impeller 29 when the impeller 29 moves to the front side during its rotation is provided at a circular plate 26b at a position on the rear side of the innermost step thereof. In a cover member 37 of the impeller 29 provided at a position facing a front partition wall 26, the center 37a of a circular plate has an opening having a size substantially the same as an opening of a cylindrical section 26a of the front partition wall 26. The edge 37a of the opening of the circular plate is formed in a ring-like shape so as to project to the front partition wall 26 side. A backflow prevention projection 37a is inserted inside the liner ring 50 of the front partition wall 26 with a predetermined gap formed between the projection 37a and the liner ring 50. A mouth ring 51 which rubbing-contacts with the liner ring 50 when the impeller 29 moves to the front side is provided at the cover member 37 at a position facing the liner ring 50. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a self-priming pump provided with a tank chamber for storing priming water and provided with an impeller that is driven to rotate in the tank chamber.

  2. Description of the Related Art Conventionally, a self-priming pump that transfers a transfer fluid to a predetermined place by sucking the transfer fluid from the suction port and discharging it to the discharge port is known. In such a self-priming pump, priming water is introduced into the tank chamber at the start of operation, and the gas remaining in the tank is discharged from the discharge port together with the priming water by rotationally driving the impeller disposed in the tank chamber, A self-priming operation is performed in which only the transfer fluid is filled in the tank.

As this type of self-priming pump, for example, the one described in Patent Document 1 is known. This self-priming pump has a gap between the inner diameter of the mouth portion of the partition plate that partitions the first casing and the second casing made of synthetic resin, and the outer diameter of the impeller (impeller) into which the tip is inserted into the mouth portion. It is intended to improve the pumping performance and pump efficiency by reducing the flow rate and limiting the transfer fluid that flows backward from the pump chamber to the suction side through the gap.
JP 2005-48675 A

  However, the above-described self-priming pump has a drawback that it is difficult to manage the inner diameter of the mouse portion and the outer diameter of the impeller.

  This invention is made | formed in view of such a point, and it aims at providing the self-priming type pump which can restrict | limit the backflow of the fluid transferred to a suction side, and can improve the efficiency of a pump.

  A self-priming pump according to the present invention includes a casing having a suction port and a discharge port for a transfer fluid, a pump chamber formed by partitioning the inside of the casing, and an introduction port communicating with the suction port at a front of the pump chamber. A front partition formed on the side, and accommodated in the pump chamber so as to be rotatable coaxially with the introduction port, and an opening for introducing the transfer fluid is formed in a portion facing the introduction port of the front partition. An impeller that discharges the transfer fluid introduced from the opening from the outer periphery, a support member that supports the impeller so as to be rotatable and slidable in the direction of the rotation axis, a rotation driving unit that rotationally drives the impeller, and At least one of the inlet of the front partition and the opening of the impeller projects in a direction parallel to the rotation axis, and the inlet of the front partition and the opening of the impeller Characterized in that a backflow prevention protrusion is covered with a non-contact rotation axis direction of the annular gap from at least one of the inner and outer circumferential sides between.

  According to the previous invention, when the impeller that is rotatably and slidably supported by the support member rotates and starts the self-priming operation, no axial thrust is generated in the impeller during the initial suction operation. An annular gap is formed between the inlet of the partition wall and the opening of the impeller, and the liquid in the pump chamber tends to flow back to the inlet side where the degree of vacuum is increased through the gap. However, since at least one of the inlet of the front partition wall and the opening of the impeller is formed with a backflow preventing protrusion that covers the annular gap in a non-contact manner from at least one of the inner peripheral side and the outer peripheral side. The labyrinth structure is applied to the fluid to be counterflowed, and the backflow is limited. As a result, a rapid pump start can be realized by preventing a reduction in vacuum on the inlet side. After the pump is started, axial thrust is generated in the impeller, and the annular gap between the front partition wall inlet and the impeller opening is closed, and the backflow of fluid in this portion is prevented. As a result, the pump efficiency can be maximized.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a cross-sectional view showing the overall configuration of the self-priming pump according to the first embodiment of the present invention.
The self-priming magnet pump includes a casing 1 and a pump body 2 mounted on the rear side of the casing 1. Hereinafter, the self-priming magnet pump is simply referred to as “pump”.

  The casing 1 is partitioned by a partition wall 5 into a first casing 3 on the front side and a second casing 4 on the rear side. At the upper part of the front side end face of the first casing 3, a suction port 3 a projects from the front side. A flange 6 is provided at the tip of the suction port 3a. Connected to the suction port 3a is a distal end portion of the suction pipe 7 that extends vertically from the lower part of the pump to the upper portion of the first casing 3 and is bent at approximately 90 degrees toward the suction port 3a at the height of the suction port 3a. Has been. A flange 7a is integrally formed at the distal end portion of the suction pipe 7, and the flange 7a of the suction pipe 7 and the flange 6 of the suction pipe 3a are fastened by screws or the like (not shown) via an O-ring 8. . On the upper surface of the first casing 3, a liquid suction hole 3 b for introducing a liquid serving as priming water into the first tank chamber 9 is formed. Note that a valve 11 is fitted in the liquid suction hole 3b via an O-ring 10, and the liquid suction hole 3b can be opened and closed by the valve 11.

  The first tank chamber 9 has three chambers extending in the vertical direction in a direction perpendicular to the drawing sheet, and only the middle suction chamber 9A is shown in the drawing. The chambers on both sides (not shown) communicate with each other via a communication chamber 9B defined by the upper partition plate 12, and communicate with the suction chamber 9A at the upper end. As a result, the liquid serving as the priming water is accumulated in the three chambers, and a sufficient amount necessary for starting the pump is secured, and the movement of the liquid in the suction chamber 9B becomes dominant during the pump operation. The upper partition plate 12 is formed with a hole 12 a penetrating in the vertical direction at a position in contact with the partition plate 5. As a result, the upper suction chamber 9A and the chambers on both sides thereof communicate with each other even at the end. A lower tank chamber 9C is provided below the connection chamber 9B via a lower partition plate 13. Further, a drainage port 3c protruding to the outside is formed at a position in contact with the bottom surface of the lower tank chamber 9C. By opening the valve 14 fitted to the drainage port 3c, the drainage of the transfer fluid from the drainage port 3c is performed. It can be performed.

  The partition plate 5 that partitions the first casing 3 and the second casing 4 is provided with a circular suction hole 5 a whose lower end is in contact with the upper partition plate 12. A hole 5b that connects the lower tank chamber 9C and the second casing 4 in the vicinity of the bottom surface is formed at a lower position of the suction hole 5a of the partition plate 5. Thereby, when the drain port 3c provided in the lower tank chamber 9C is opened, the transfer fluid accumulated near the bottom surface in the second casing 4 can be discharged through the drain hole 3c.

  The second casing 4 includes a second tank chamber 20 that accommodates a transfer fluid and a part of the pump body 2 therein. The internal space of the second tank chamber 20 is divided into a lower tank chamber 20B that generates a vortex by the partition plate 21 and the like, and a discharge chamber 20A that communicates with the lower tank chamber 20B.

  A protruding port 4a protruding upward is formed at the upper end of the second casing 4, and a flange 22 is provided at the tip of the discharge port 4a. The discharge port 4a is connected to the rear end portion of the discharge pipe 23 extending upward from the upper end of the pump. A flange 23a is integrally formed at the rear end portion of the discharge pipe 23, and the flange 23a of the discharge pipe 23 and the flange 22 of the discharge port 4a are connected by a screw or the like (not shown) through an O-ring 24. Has been.

  An opening 4b is formed in the rear side surface below the second casing 4, and the pump chamber portion of the pump body 2 is mounted in the lower tank chamber 20B from the opening 4b.

  FIG. 2 is an enlarged cross-sectional view of the pump body 2 in FIG. The pump body 2 has a front partition wall 26 that defines the inside of the second casing 4 and forms a pump chamber 28 therein, and a cylindrical space that communicates with the pump chamber 28 and protrudes from the opening 4b on the rear side surface to the rear side. A bottomed cylindrical rear partition wall 27 made of a nonmagnetic material such as a resin, a support shaft 39 projecting from the rear side bottom surface of the rear partition wall 27 to the front side, and a cylindrical shape on the support shaft 39 A cylindrical driven rotator 30 that is coaxially supported so as to be rotatable and slidable via a bearing 40, and an impeller 29 that is coaxially and integrally mounted on the front side of the driven rotator 30 and rotates in the pump chamber 28. A drive rotator 33 that is magnetically coupled to the driven rotator 30 via the rear partition wall 27 and rotationally drives the driven rotator 30, a motor 34 that rotationally drives the drive rotator 33, and an outer side of the drive rotator 33. Covering It is constituted by a cylindrical driving member casing 31.

  The front partition wall 26 is connected to a suction hole 5a formed on the partition plate 5 on the front side, and a cylindrical portion 26a whose base end side is an inlet 26c for a fluid to be transferred to the pump chamber 28, and a base end side of the cylindrical portion 26a. And a disk portion 26 b that expands the diameter and forms the front side wall portion of the pump chamber 28. A liner ring 50 is attached to the inlet 26 c of the front partition wall 26. Holes 26 d and 26 e for communicating the lower tank chamber 20 </ b> B of the second casing 4 and the pump chamber 28 are formed below the disc portion 26 b of the front partition wall 26. The disc part 26 b of the front partition wall 26 is fitted with a ring-shaped partition wall 4 d that protrudes toward the inside of the second casing 4 along the opening 4 b formed on the rear side surface of the second casing 4. Thus, a pump chamber 28 is formed. A step portion 4 c is formed at the edge of the opening 4 b of the second casing 4, and the opening edge portion 27 a of the rear partition wall 27 is fitted to the step portion 4 c via the O-ring 25, whereby the rear partition wall 27. The inside of is sealed.

  The driven rotator 30 includes a cylindrical rotator 30a and a driven magnet 41 embedded on the outer peripheral side of the cylindrical rotator 30a. An impeller 29 is attached to the front end of the driven rotor 30. The impeller 29 includes a circular plate 35, a plurality of blades 36 formed on the front side of the circular plate 35, and an annular cover joined so as to sandwich the plurality of blades 36 in pairs with the circular plate 35. Member 37. An opening 37 a is formed at the center of the cover member 37, and a mouth ring 51 is attached to the periphery of the opening 37 a so as to face the liner ring 50 of the front partition wall 26.

  On the other hand, a thrust bearing 38 is provided on the proximal end side of the central axis of the disc 35 so as to make pinpoint contact with the distal end of the support shaft 39. A predetermined annular gap is formed between the liner ring 50 and the mouth ring 51 in a state where the thrust bearing 38 is in contact with the front end surface of the support shaft 39. Thus, when the impeller 29 moves to the front side along the support shaft 39, the mouth ring 51 comes into sliding contact with the liner ring 50, and when the impeller 29 moves to the rear side along the support shaft, the thrust ring The bearing 38 comes into pinpoint contact with the tip surface of the support shaft 39. The opening 37a of the impeller 29 is formed with a ring-shaped backflow prevention protrusion 37b that protrudes to the front side and covers the annular gap between the liner ring 50 and the mouth ring 51 from the inner peripheral side without contact. Yes.

  The drive rotator 33 has a cylindrical rotator 33a and a drive magnet 42 embedded on the inner periphery thereof. A rotating shaft of the motor 34 is fixed to the rear side surface of the drive rotating body 33. The drive magnet 42 is magnetically coupled to the driven magnet 41 via the rear partition wall 27, and rotationally drives the driven magnet 41 by the rotational driving force from the motor 34.

  Next, the operation of the pump configured as described above will be described.

  First, prior to the self-priming operation, a transfer fluid serving as priming water is introduced from the liquid suction hole 3b of the first casing 3, and the suction pipe 7, the first casing 3, and the second casing 4 are filled with the transfer fluid. At this time, the liquid level of the transfer fluid in the first casing 3 is equal to the height of the lowest point of the suction port 3a, and the top is filled with gas.

  Next, when the drive rotating body 33 is rotationally driven by the motor 34, the impeller 29 is rotationally driven through the driven rotating body 30, and the self-priming operation is started. Thereby, the transfer fluid and the residual gas in the first tank chamber 9 are sucked into the opening 37a of the impeller 29 and discharged from the outer peripheral side of the impeller 29 by the centrifugal force of the impeller 29, whereby the second tank chamber 20 It is transferred to.

  Thus, the transfer fluid and gas transferred from the first tank chamber 9 to the second tank chamber 20 repeat gas-liquid separation on the liquid surface of the second tank chamber 20, and the separated gas is discharged from the discharge port 4a. Discharged to the side. During the initial suction operation when the self-priming operation is started, the axial thrust toward the front is not generated on the impeller 29, and the axial thrust toward the rear side is generated conversely, so that the thrust bearing 38 is the tip surface of the support shaft 38. The impeller 29 is retracted to a position where it comes into contact, and the largest annular gap is formed between the inlet of the front partition and the opening of the impeller. As a result, the liquid containing some bubbles in the pump chamber 28 tends to flow back to the inlet 26c side where the degree of vacuum is increased through the annular gap.

  However, since the protrusion 37b for backflow prevention that covers the annular gap from the inner periphery side in a non-contact manner is formed at the tip of the impeller 29, the protrusion 37b has a labyrinth structure for the fluid to be backflowed, Backflow will be limited.

  As a result, a rapid pump start is realized by preventing a decrease in the degree of vacuum on the inlet 26c side. After the pump is started, an axial thrust force directed toward the front is generated on the impeller 29, the impeller 29 slides to the front side, the liner ring 50 and the mouth ring 51 come into contact with each other, and an annular gap between the two Is closed. Therefore, the backflow of the fluid in this part is prevented. As a result, the pump efficiency can be maximized.

  Table 1 shows the self-priming operation time of the conventional pump and the pump according to the first embodiment of the present invention when the suction height is 4 m. Thus, compared with the conventional pump, the pump according to the first embodiment of the present invention has a labyrinth structure, so that it is 13.40% in the first test, and 20.45% in the second and third tests. The suction operation time was shortened.

(Second Embodiment)
FIG. 3 is an enlarged cross-sectional view of a self-priming pump according to the second embodiment of the present invention. In addition, since it is the same structure as 1st Embodiment except the shape of an impeller, the description is abbreviate | omitted.

  In the first embodiment, only the backflow preventing projection 37b that covers the annular gap between the front partition wall 26 and the impeller 29 from the inner peripheral side is formed. However, in the second embodiment, this annular gap is formed in the inner gap. A backflow prevention projection 37Ab that covers from the circumferential side and a backflow prevention valve 37Ac that covers from the outer side are provided on the impeller 29 side.

  A ring-shaped first backflow prevention projection 37Ab projecting toward the front partition wall 26 is formed at the edge of the opening 37Aa of the cover member 37A of the impeller 29A, and the outer periphery of the projection 37Ab is lowered to the rear side. A ring-shaped backflow preventing protrusion 29Ab protruding toward the front partition wall 26 is formed through the ring 51. That is, the backflow preventing protrusions 29Ab and 29Ac are formed in a double manner via the mouth ring 51. In the gap between the first backflow prevention protrusion 29Aa and the second backflow prevention protrusion 29Ab, a liner ring 50 protruding from the counterpart front partition wall 26 is disposed via a predetermined gap. The annular clearance between the backflow preventing protrusions 29Ab and 29Ac and the liner ring 50 is formed in a multi-stage crank shape.

In this way, by forming the double backflow preventing protrusion on the impeller 29A side, the labyrinth structure of the gap between the front partition wall 26 and the impeller 29A can be configured more complicatedly. The backflow of the gas impinging on the suction side of the impeller 29A can be more effectively prevented.
(Third embodiment)
FIG. 4 is an enlarged cross-sectional view of a self-priming pump according to the third embodiment of the present invention. In addition, since it is the same structure as 1st Embodiment except the shape of a front partition and an impeller, the description is abbreviate | omitted.

  In the third embodiment, the backflow prevention protrusion that is integrally formed on the impeller 29 side in the first embodiment is arranged on the front partition wall 26B side.

  The front partition wall 26B includes a cylindrical portion 26Ba and a plurality of stages of disk portions 26Bb that are connected to the opening end and have a diameter that increases toward the rear side. A ring-shaped backflow prevention protrusion 26Bc protruding rearward is formed on the inner diameter of the disk part 26Bb. The backflow prevention protrusion 26Bc is arranged so as to be inserted through a predetermined gap on the inner peripheral side of the mouth ring 51 provided on the other impeller 29B. The impeller 29B is not provided with a backflow prevention protrusion.

As described above, the effect of the present invention can be obtained even when the backflow preventing protrusion 26Bc is provided on the front partition wall 26B side.
(Fourth embodiment)
FIG. 5 is an enlarged cross-sectional view of a self-priming pump according to the fourth embodiment of the present invention. In the third embodiment, only the backflow prevention protrusion 26Bc that covers the annular gap between the front partition wall 26B and the impeller 29B from the inner peripheral side is formed. However, in the fourth embodiment, the front partition wall 29C has a front surface. A backflow prevention protrusion 26Cc covering the inner periphery of the annular gap between the partition wall 26B and the impeller 29B and a backflow prevention protrusion 29Cd covering the outer periphery are provided.

  The front partition wall 26C includes a cylindrical portion 26Ca and a plurality of stages of disk portions 26Cb that are connected to the opening end and have a diameter that increases toward the rear side. A ring-shaped first backflow prevention protrusion 26Cc protruding rearward is formed on the inner diameter of the disk part 26Cb, and a liner ring 50 is provided on the outer periphery of the first backflow prevention protrusion 26Cc. A ring-shaped second backflow prevention protrusion 26Cd protruding to the rear side is formed. Between the first backflow prevention protrusion 26Cc and the second backflow prevention protrusion 26Cd protruding to the rear side, a mouth ring 50 protruding from the other impeller 29 is interposed. Therefore, a multi-stage labyrinth structure is formed between the first backflow prevention protrusion 26 </ b> Cc, the second backflow prevention protrusion 26 </ b> Cd, and the mouth ring 50.

Thus, even if it comprises so that several protrusions for backflow prevention may be provided in the front partition side, the effect of this invention can be show | played.
(Fifth embodiment)
FIG. 6 is an enlarged cross-sectional view of a self-priming pump according to the fifth embodiment of the present invention. In addition, since it is the same structure as 1st Embodiment except the shape of a front partition, the description is abbreviate | omitted.

  In the first embodiment, the backflow preventing protrusion 29b is formed on the impeller 29 side. In the fifth embodiment, in addition to the backflow preventing protrusion 29a provided on the impeller 29 side, the front partition wall is further provided. A backflow prevention protrusion 26Dc is also formed on the 26D side. In addition, since the structure of the impeller 29 is the same as 1st Embodiment, the description is abbreviate | omitted.

  The front partition wall 26D includes a cylindrical portion 26Da and a plurality of stages of disk portions 26Db connected to the rear side of the cylindrical portion 26Da. A liner ring 50 is provided on the inner diameter of the disc portion 26Db, and a ring-shaped backflow prevention projection 26Dc projecting rearward is formed on the outer periphery of the liner ring 50. Thus, even if it comprises so that the protrusion for backflow prevention may be provided in the both sides of front partition 26D and impeller 29, there can exist the effect of this invention.

  The number of the backflow prevention protrusions provided in the above embodiment is not limited to one or two, and any number of backflow prevention protrusions may be provided on at least one of the front partition wall side or the impeller side. Can be formed.

  Further, the backflow prevention protrusion may not be formed integrally with the front partition wall and the impeller, and may be configured to be attached with another member. Furthermore, the shape of the backflow prevention protrusion does not necessarily have to be formed in a ring shape, and any shape can be used as long as it forms a labyrinth structure in the annular gap between the front partition wall and the impeller. Good.

  In the above embodiment, the present invention is applied to a pump having a structure in which the driven rotator 30 rotates with respect to the support shaft 39. However, the present invention is also applied to a pump having a rotating shaft that rotates integrally with the driven rotator. Is possible.

It is sectional drawing of the self-priming pump which concerns on 1st Embodiment. It is an expanded sectional view of FIG. It is an expanded sectional view of the self-priming pump concerning a 2nd embodiment. It is an expanded sectional view of the self-priming pump concerning a 3rd embodiment. It is an expanded sectional view of the self-priming pump concerning a 4th embodiment. It is an expanded sectional view of the self-priming pump concerning a 5th embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Casing 2 ... Pump main body 3 ... 1st casing 4 ... 2nd casing 5 ... Partition plate 9 ... 1st pump chamber 20 ... 2nd pump chamber 29 ... Impeller 50 ... Liner ring 51 ... Mouth ring

Claims (4)

A casing having a suction port and a discharge port for the transfer fluid;
A front partition wall that partitions the inside of the casing to form a pump chamber and forms an inlet port that communicates with the suction port on the front side of the pump chamber;
The pump chamber is rotatably accommodated coaxially with the introduction port, and an opening for introducing the transfer fluid is formed in a portion facing the introduction port of the front partition, and is introduced from this opening. An impeller for discharging the transfer fluid from the outer periphery;
A support member that supports the impeller rotatably and slidably in the direction of the rotation axis;
A rotation driving means for rotating the impeller;
At least one of the inlet of the front partition and the opening of the impeller protrudes in a direction parallel to the rotation axis, and an annular clearance in the direction of the rotation axis is formed between the inlet of the front partition and the opening of the impeller. A self-priming pump, comprising: a backflow preventing projection that covers the inner and outer peripheral sides of at least one of them in a non-contact manner. The front partition has a liner ring at the inlet,
The impeller has a mouth ring that can slide on the liner ring at the opening,
The self-priming pump according to claim 1, wherein the backflow preventing protrusion covers an annular gap between the liner ring and the mouth ring from at least one of an inner peripheral side and an outer peripheral side thereof. A bottomed cylindrical rear partition wall that forms a columnar space communicating with the pump chamber on the rear side of the casing;
The support member includes a support shaft protruding from the rear side bottom surface of the rear partition wall to the front side,
The rotation driving means is a driven rotating body provided integrally with the impeller and disposed in an annular space between the rear partition wall and the support shaft and rotatably supported by the support shaft. The self-priming pump according to claim 1, further comprising: a drive rotator that is disposed and magnetically coupled to the driven rotator, and a motor that rotationally drives the drive rotator. The casing is divided into a first tank chamber on the front side and a second tank chamber on the rear side that can store priming water,
The first tank chamber communicates with an inlet of the transfer fluid at an upper portion thereof and communicates with an inlet of the front partition at a lower portion thereof.
The self-priming type according to any one of claims 1 to 3, wherein the second tank chamber communicates with the pump chamber and communicates with the discharge port of the transfer fluid at an upper portion thereof. pump.

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