JP2004278404A - Self-priming pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a self-priming pump not needing connection of an internal suction pipe inside an enclosure of a water heater or the like, capable of having an external suction tube directly connected at the lower edge of the enclosure. <P>SOLUTION: A pump cover 3 which is a resin composition of the self-priming pump has a suction tube connecting part 28' protruding toward the lower center, and a connecting tube passage 40, for communicating to each other the suction tube connecting part 28' with a central introducing space H' of a closed annular groove facing the center of a centrifugal type impeller 15, passes through a water collecting chamber 12 at a shortest distance. An opening 40a of the connecting tube passage 40 is positioned at the substantially highest part of the outer peripheral contour of a thrust bearing part 11. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a self-priming pump incorporated in a water heater, for example, and used as a circulating pump for reheating a bath, and more particularly to a self-priming pump having a suction pipe joint protruding downward. About.
[0002]
[Prior art]
3 and 4 show a conventional self-priming pump. 3 is a longitudinal sectional side view showing a state in which the prime mover side is omitted, FIG. 4A is a front view of an impeller case showing a state seen along line EE in FIG. 3, and FIG. 3 is a rear view of the pump cover showing a state seen along line FF in FIG. 3, and FIG. 4C is a front view of a partition plate showing a state seen along line EE in FIG. .
[0003]
As shown in FIG. 3, the self-priming pump includes a motor housing 1 containing a motor (motor), an impeller case (pump casing) 2 joined to the front end face, and a front end face of the impeller case 2. It has a pump cover (end casing) 3 which is overlapped with a partition plate 5 and a rubber packing 6 interposed therebetween, and has a laminated structure interconnected by mounting bolts (not shown).
[0004]
A drive magnet disk 22 is fixed to the end of the motor shaft 8 of the motor housing 1. After the ceramic washer 19a is fitted to the base of the fixed shaft 7 in the horizontal posture implanted in the partition plate 18, the centrifugal impeller 4 is fitted. The ceramic washer 19b is fitted to the D-shaped tip of the fixed shaft 7. are doing.
[0005]
As shown in FIG. 4A, the impeller case 2 has an impeller chamber 15 having a disk-shaped space for accommodating the centrifugal impeller 4 so as to be rotatable, and is oriented obliquely upward from a discharge port 16a of the impeller chamber 15. Between the discharge flow path 16 and the upper jet port 16b of the discharge flow path 16 and the outer peripheral wall of the impeller chamber 15. The air-water mixed fluid discharged from the jet port 16b during the self-priming operation is air and water. And a recirculation groove 30 formed by cutting out a part of the outer peripheral wall of the impeller chamber 15 and returning water from the air / water separation chamber 17 into the impeller chamber 15. As shown in FIG. 3, the centrifugal impeller 4 includes a back shroud 4e having a driven magnet disk 4a built therein, a plurality of spiral blades 4b provided on the back shroud 4e, and a ring covering the front outer peripheral side of the spiral blade 4b. And a plate front shroud 4c.
[0006]
As shown in FIG. 4B, the pump cover 3 is partitioned by a suction pipe joint 28 and a discharge pipe joint 29 projecting upward, an outer wall and a partition wall 13a oriented in the axial direction, and the pump cover 3 A thrust bearing 11 having a receiving hole h for receiving the D-shaped tip of the fixed shaft 7 of the centrifugal impeller 4, and an opening communicating with the partitions 13 a and 13 b around the thrust bearing 11. A central introduction space H which is defined by an annular wall 14, faces the central portion of the centrifugal impeller 4, and communicates the suction chamber 9 and the impeller chamber 15 with each other, and a weir portion 13c for returning the outer wall and the partition 13a and bubbles upward. And a sump for storing priming water for supplying at least to the impeller chamber 15 at the time of self-priming operation, which is located substantially below the impeller rotation center line. And a 12.
[0007]
A baffle plate portion 14a projecting downward from the open annular wall 14 is provided in the water reservoir chamber 12. Here, the air-water separation section at the time of the self-priming operation includes not only the air-water separation chamber 17 of the impeller case 2 but also the upper part of the pump cover 3 on the discharge chamber 10 side. The priming water returns to the sump chamber 12 as return water. In addition, 12a is a communication port for connecting a hot water supply circuit of a different system from the suction pipe joint 28.
[0008]
As shown in FIG. 4 (c), the partition plate 5 has a circular through-hole 24 corresponding to the central inflow passage H, and at least the priming water in the sump chamber 12 of the pump cover 3 at the time of the self-priming operation. A water supply port 27 for replenishing the chamber 15, a recirculation port 26 for returning water in the steam separator 17 to the discharge chamber 10, and a notch for passing an upper fluid in the steam separator 17 to the upper part of the discharge chamber 10. And a distribution port 25. The rubber packing 6 (not shown) also has an opening similar to that of the partition plate 5.
[0009]
When the pump is started (self-priming operation: priming state), the priming water in the sump chamber 12 is supplied into the impeller chamber 15 through the water inlet 27, so that water and bubbles generated by the stirring action of the rotating impeller 4 are removed. The air-water mixed fluid collides with the upper recoil barrier 17a from the jet port 16b through the discharge flow path 16, air bubbles are sent out to the discharge pipe joint portion 29 through the flow port 25, and the separated water flows through the flow port. The water returns to the sump chamber 12 as return water from the discharge port 25 through the discharge port 25 or 25. By repeating the bubble bleeding and the priming recovery by such air / water separation, the pressure in the suction chamber 9 is gradually reduced, and the central part of the impeller 4 in the impeller chamber 15 from the suction chamber 9 via the central introduction space H. Since the water is sucked, the operation shifts to the suction / pumping operation (pumping operation) at the end of the operation in the priming state. In addition, W in FIGS. 3 and 4 indicates a water flow, and I indicates the rotation direction of the impeller 4.
[0010]
[Problems to be solved by the invention]
The self-priming pump having the above configuration is incorporated in a water heater housing containing a heat exchanger, for example. During the self-priming operation, the air bubbles separated in the water / water separation chamber 17 need to be pulled upward through the discharge pipe joint 29, so that the discharge pipe joint 29 protrudes upward from the pump cover 3 and the water heater case. The self-priming pump is usually disposed below the heat exchanger, and a first internal discharge pipe (not shown) is connected between the discharge pipe joint 29 and the heat exchanger. A second internal discharge pipe (not shown) is connected between the heat exchanger and an external discharge pipe joint at the lower end of the water heater housing. On the other hand, an internal suction pipe (not shown) is connected between the suction pipe fitting part 28 of the self-priming pump and the external suction pipe fitting at the lower edge of the water heater housing.
[0011]
However, in the pump cover 3, since the suction pipe joint 28 protrudes upward similarly to the discharge pipe joint 29, the suction pipe joint 28 is drawn from the suction pipe joint 28 to the external suction pipe joint at the lower edge of the water heater housing. And the external suction pipe cannot be directly connected to the self-priming pump at the lower edge of the water heater housing. For this reason, the number of parts increases by the amount of the internal suction pipe, and the cost of the water heater is increased due to an increase in the load of the assembling work. Furthermore, since it is necessary to secure a piping space in the water heater, the downsizing of the water heater is impaired.
[0012]
In view of the above problems, it is an object of the present invention to provide a self-priming pump that can eliminate the need for connecting an internal suction pipe in a housing such as a water heater and that can directly connect an external suction pipe at a lower edge of the housing. Is to do.
[0013]
[Means for Solving the Problems]
The basic configuration of the self-priming pump according to the present invention includes an impeller chamber that accommodates a centrifugal impeller rotatably around a substantially horizontal axis as a rotation center, and a centrifugal pump that communicates with the impeller chamber through a water inlet. A sump chamber defined in a lower region from the rotation center line of the impeller to store priming water, and a water / water mixed fluid scraped upward from the impeller chamber by the rotation of the centrifugal impeller during self-priming operation. It communicates with the steam-water separation chamber for separation and the discharge pipe joint for discharging the gas separated in the steam-water separation chamber upward during self-priming operation, and the separated priming water as return water. A discharge chamber to be returned to the sump chamber, and a central introduction space facing the center of the centrifugal impeller and surrounding the water sump and the discharge chamber are provided.
[0014]
Further, the present invention is characterized in that a connecting pipe for interconnecting the suction pipe joint part projecting downward and the central introduction space is formed through the water reservoir chamber.
[0015]
It is desirable that this connection conduit be formed as a partially formed portion of the pump cover as a molded product. However, in order to eliminate the slider forming die used for forming the suction pipe joint and the pipe hole of the connection pipe, the surface of the rubber packing or the partition plate to be joined to the pump cover is used as a partial pipe wall of the connection pipe. However, the above partially formed portion may be formed as an open channel in units of the pump cover.
[0016]
During the self-priming operation, the priming water collects on the outer peripheral side of the impeller, so that the priming water is supplied to the impeller chamber through the water inlet, so that the self-priming operation can be performed. Then, the water level in the connection pipe line gradually rises due to the self-priming operation, and the operation shifts to the pumping operation as the water overflows into the central introduction space.
[0017]
As described above, since the suction pipe fitting part protruding downward is provided, the external suction pipe can be directly connected to the suction pipe fitting part of the self-priming pump at the lower edge of the housing of the water heater or the like, A low-cost and compact water heater can be realized without requiring the connection of the internal suction pipe. In addition, since water can be guided directly to the central introduction space via the connecting pipe line without passing through the suction chamber at the upper position, the self-priming pump can be expected to be more compact because the suction chamber becomes unnecessary. Furthermore, since a suction chamber and a drawing internal suction pipe are not required, and the shortest connection to the central guide space by the connection pipe can be realized, the amount of air bleeding during the self-priming operation can be reduced. Further, since the pipe resistance loss can be suppressed, improvement in pumping performance can also be expected.
[0018]
In addition, as effective use of the empty space of the suction chamber, the suction chamber space and the sump chamber are communicated with each other, the discharge chamber is expanded in the suction chamber space, and the return path of the return water of the discharge chamber to the sump chamber is provided. The direction of rotation of the impeller is opposite to that of the impeller, and it can be formed as a non-vertical inclined flow path through the suction chamber space, so that the steam-water separation function becomes active in the discharge chamber and contributes to shortening the self-priming time. .
[0019]
It is desirable that the level of the connecting pipe opening toward the central introduction space be equal to or higher than the priming water level in the central introduction space during the self-priming operation. This is because the amount of priming water can be secured.
[0020]
The central introduction space is a closed loop groove extending around the thrust bearing for receiving the tip of the shaft, and the connecting conduit is opened at almost the uppermost part of the outer peripheral contour of the thrust bearing. In such cases, sufficient priming volume can be secured.
[0021]
By arranging the connecting pipe vertically below the center introduction space in the vertical direction, the pipe length can be minimized.However, by offsetting it slightly to the discharge chamber side, air bubbles return upward. It functions as a weir and baffle. Further, the discharge pipe joint path and the suction pipe joint section can be aligned on a single vertical line.
[0022]
The connection pipe line communicating with the suction pipe joint is not limited to a form that passes only through the sump chamber, but also partially passes through the sump chamber, bypasses the discharge chamber and the like, and then communicates with the central introduction space. No problem. Since the opening on the center introduction space side faces downward, sufficient priming volume can be secured.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0024]
1A is a front view of an impeller case in a self-priming pump according to an embodiment of the present invention, FIG. 1B is a rear view of a pump cover, FIG. 1C is a front view of a partition plate, FIG. FIG. 2A is a partial cross-sectional view showing a state cut along the line AA in FIG. 1B, and FIG. 2B is a longitudinal sectional rear view of the pump cover shown in FIG. 1B.
[0025]
The self-priming pump according to the present embodiment also has a motor housing (not shown) containing a motor, and an impeller connected to the front end face, similarly to the configuration of the self-priming pump shown in FIGS. A case (pump casing) 2, a pump cover (end casing) 3 which is overlapped on a front end face of the impeller case 2 with a partition plate 5 and a rubber packing (not shown) interposed therebetween, and mounting bolts (see FIG. (Not shown) or the like.
[0026]
As shown in FIG. 1A, the impeller case 2 has an impeller chamber 15 having a disk-shaped space for accommodating the centrifugal impeller 4 so as to be rotatable, and is oriented obliquely upward from a discharge port 16a of the impeller chamber 15. And a gas-water mixed fluid discharged from the jet port 16b during the self-priming operation is partitioned between the discharge channel 16 and the upper jet port 16b of the jet channel 16 and the outer peripheral wall of the impeller chamber 15. And a recirculation groove 30 formed by cutting out a part of the outer peripheral wall of the impeller chamber 15 and returning water from the air / water separation chamber 17 into the impeller chamber 15. The centrifugal impeller 4 includes a rear shroud 4e containing a driven magnet disk (not shown), a plurality of spiral blades 4b provided on the rear shroud 4e, and an annular plate covering the front outer peripheral side of the spiral blade 4b. And a front shroud 4c.
[0027]
As shown in FIG. 1B, the pump cover 3 is defined by a suction pipe joint 28 'projecting downward in the center and a discharge pipe joint 29 projecting upward, an outer wall and a partition wall 13a oriented in the axial direction. A thrust bearing 11 having a receiving hole h for receiving the D-shaped tip of the fixed shaft of the centrifugal impeller 4, an empty room 9 ′, a closed annular wall 14 ′ around the thrust bearing 11, A discharge chamber 10 defined by a central introduction space H ′ of a closed loop groove facing the central part of the impeller 4, the outer wall and the partition 13 a, and a weir 13 c returning air bubbles upward, and communicating with the discharge pipe joint 29. A water storage chamber 12 is provided which is located substantially below the impeller rotation center line and stores priming water for replenishment to the impeller chamber 15 at least during the self-priming operation.
[0028]
A baffle (barrier portion) 14a projecting downward from the closed annular wall 14 'is provided in the water reservoir chamber 12. Here, the air-water separation section during the self-priming operation includes not only the air-water separation chamber 17 on the impeller case 2 side but also the upper area of the bulging wall 10a in the discharge chamber 10 on the pump cover 3 side. The separated priming water in the chamber 10 returns to the sump chamber 12 as return water.
[0029]
As shown in FIG. 4 (c), the partition plate 5 has a circular through hole 24 corresponding to the central inflow passage H, and at least the priming water in the sump chamber 12 of the pump cover 3 at the time of the self-priming operation. A water supply port 27 for replenishing the chamber 15, a recirculation port 26 for returning water in the steam separator 17 to the discharge chamber 10, and a notch for passing an upper fluid in the steam separator 17 to the upper part of the discharge chamber 10. And a distribution port 25. The rubber packing 6 (not shown) also has an opening similar to that of the partition plate 5.
[0030]
The center introduction space H 'and the suction pipe joint 28' projecting downward communicate with each other through a connection pipe 40. The connection pipe 40 is formed vertically below the central introduction space H in the vertical direction, and passes through the water reservoir 12 at the shortest distance. The cross-sectional area of the connecting pipe section 40 is smaller than the cross-sectional area of the water storage chamber 12, and the water storage chamber 12 is not divided into right and left by the connecting pipe section 40. The upper portion of the connection pipe 40 penetrates through the thrust bearing portion 11 from the closed annular wall 14 ', and as shown in FIG. 2, opens at the uppermost portion of the outer peripheral contour (40a). The pump cover 3 is a resin molded product, and the connection conduit 40 is formed as a partially molded portion.
[0031]
In this way, even if the opening 40a of the connection pipe 40 is formed in the central introduction space H ', the priming water is stored in the water reservoir chamber 12 below that level, and the outer periphery of the impeller 4 during the self-priming operation. Since priming water is collected on the side, priming water is supplied to the impeller chamber 15 through the water inlet 27, so that the self-priming operation is not impaired. Then, the water level in the connection pipe line 40 gradually rises due to the self-priming operation, and the operation shifts to the pumping operation due to the overflow into the central introduction space H ′. Therefore, since the suction pipe joint 28 'protruding downward is provided, it is possible to directly connect the external suction pipe to the suction pipe joint 28' of the self-priming pump at the lower edge of the housing of the water heater or the like. It is possible to realize a low-cost and compact water heater or the like without the necessity of connecting and connecting the internal suction pipe. In addition, since water can be guided directly to the central introduction space without passing through the upper suction chamber, the size of the self-priming pump can be expected to be reduced because the suction chamber (empty chamber 9 ') is not required. Furthermore, since a suction chamber (empty chamber 9 ') and a drawing internal suction pipe are not required, and the shortest connection to the central guide space H' by the connection pipe line 40 can be realized, the amount of air bleed during the self-priming operation can be reduced. Further, since the pipe resistance loss can be suppressed, improvement in pumping performance can also be expected.
[0032]
【The invention's effect】
As described above, since the suction pipe joint portion protruding downward is provided, it is possible to directly connect the external suction pipe to the suction pipe joint portion of the self-priming pump at the lower edge of the housing of the water heater or the like. It is possible to realize a low-cost and compact water heater or the like without the necessity of connecting and connecting the internal suction pipe. In addition, since water can be guided directly to the central introduction space without passing through the upper suction chamber, the size of the self-priming pump can be expected to be reduced because the suction chamber becomes unnecessary. Furthermore, since a suction chamber and a drawing internal suction pipe are not required, and the shortest connection to the central guide space by the connection pipe can be realized, the amount of air bleeding during the self-priming operation can be reduced. Further, since the pipe resistance loss can be suppressed, improvement in pumping performance can also be expected.
[Brief description of the drawings]
1A is a front view of an impeller case in a self-priming pump according to an embodiment of the present invention, FIG. 1B is a rear view of a pump cover, and FIG. 1C is a front view of a partition plate.
2A is a partial cross-sectional view showing a state cut along line AA in FIG. 1B, and FIG. 2B is a longitudinal rear view of the pump cover shown in FIG. 1B. .
FIG. 3 is a vertical sectional side view showing a state in which a prime mover side is omitted in a conventional self-priming pump.
4 (a) is a front view of an impeller case showing a state seen along line EE in FIG. 3, and FIG. 4 (b) shows a state seen along line FF in FIG. FIG. 4C is a rear view of the pump cover, and FIG. 4C is a front view of the partition plate showing a state seen along line EE in FIG. 3.
[Explanation of symbols]
2. Impeller case (pump casing)
3. Pump cover (end casing)
Reference Signs List 4 Centrifugal impeller 4b Spiral blade 4c Front shroud 4e Back shroud 5 Partition plate 9 Suction chamber 9 'Empty chamber 10 Discharge chamber 10a Swelling wall 11 Thrust bearing 12 Water reservoir chamber 13a .., 13b ... partition 13c ... dam 14 '... closed annular wall 14a ... baffle 15 ... impeller chamber 16 ... discharge passage 16a ... scraping port 16b ... jet outlet 17 ... gas-water separation chamber 18 ... partition plate 24 ... circular through-opening 25 ... distribution port 26 ... reflux port 27 ... water supply ports 28 and 28 '... suction pipe joint part 29 ... discharge pipe joint part 30 ... reflux groove 40 ... connection conduit 40a ... opening h ... receiving hole H' ... central part introduction space I: impeller 4 rotation direction W: water flow

Claims (5)

An impeller chamber accommodating the centrifugal impeller rotatably about a substantially horizontal axis as a center of rotation; and an impeller chamber communicating with the impeller chamber via a water inlet, and being defined in a region below the rotation center line of the centrifugal impeller. A sump chamber for storing priming water, a steam-water separation chamber for separating steam-water mixed fluid that is scraped upward from the impeller chamber by rotation of the centrifugal impeller during the self-priming operation, and a self-priming chamber. A discharge which is connected to a discharge pipe joint for discharging the gas separated in the water / water separation chamber upward during the suction operation, and which returns the separated priming water as return water to the water storage chamber. A self-priming pump comprising a chamber and a central introduction space facing the central part of the centrifugal impeller and surrounding the sump chamber and the discharge chamber.
A self-priming pump, characterized in that a connecting conduit for interconnecting the central introduction space and a downwardly projecting suction pipe joint portion passes through the water reservoir. 2. The pump chamber according to claim 1, wherein the sump chamber, the discharge chamber, and the center introduction space are defined in a pump cover as a molded product, and the connection conduit is formed as a partially molded portion of the pump cover. A self-priming pump characterized by being constituted. 3. The self-priming device according to claim 1, wherein a level of the connection pipe opening toward the central introduction space is equal to or higher than a priming water level in the central introduction space during the self-priming operation. 4. Suction pump. 3. The thrust bearing portion according to claim 1, wherein the center introduction space is a closed loop groove surrounding a thrust bearing portion for receiving a tip portion of the shaft. A self-priming pump characterized by being open to the uppermost part of the contour. The self-priming pump according to any one of claims 1 to 4, wherein the connection pipe is disposed vertically below the central introduction space in a vertical direction.

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