JP7403792B2 - drain pump - Google Patents

Description

The present invention relates to a drain pump used, for example, to discharge drain water from an air conditioner.

An air conditioner installed indoors has a drain pan that receives drain water condensed on the surface of an indoor heat exchanger, and a drain pump that discharges drain water from the drain pan.

An example of a conventional drainage pump is shown in FIG. A drain pump 801 shown in FIG. 4 has a rotary blade 830 in a housing 810 that scoops up drain water. The rotary blade 830 has a large diameter blade 833 extending in the radial direction, a small diameter blade 834 connected to the lower part of the large diameter blade, and a ring member 850 that covers the outer circumference of the large diameter blade. A drainage pump having such a configuration is disclosed in Patent Document 1 and the like.

As schematically shown in FIG. 4, the drain water scooped up by the rotating blades 830 in the drain pump 801 becomes a rotating flow centered on the gas-liquid boundary surface S whose cross section is a quadratic curve. In FIG. 4, the area filled with dots indicates drain water, and the area where the dot density is relatively high indicates that the water pressure is comparable to that of the drain water in the discharge pipe 818. The same applies to FIG. Then, as shown by arrow F, the drain water overcomes the ring member 850 due to centrifugal force and heads toward the discharge pipe 818. At this time, by scraping the drain water near the gas-liquid interface S at the upper end of the large-diameter blade 833, the drain water and air are mixed and bubbles are generated. These bubbles cause noise.

In order to suppress such noise, it is possible to employ the drainage pump disclosed in Patent Document 2. FIG. 5 shows a drainage pump having the same configuration as the drainage pump of Patent Document 2. The rotary blade 930 of the drainage pump 901 shown in FIG. It has a lower plate 936 and an annular upper plate 938 that connects the upper ends of the large diameter blades 933.

As schematically shown in FIG. 5, the drain water scraped up by the rotating blades 930 in the drain pump 901 becomes a rotating flow centered on the gas-liquid interface S whose cross section is a quadratic curve, but it rises. The flow of drain water hits the upper plate 938 and heads toward the discharge pipe 918 as indicated by arrow F. This eliminates the possibility of scraping rising drain water at the upper end of the large-diameter blade 933. Therefore, generation of bubbles is suppressed and noise is reduced.

Japanese Patent Application Publication No. 2006-177184 Japanese Patent Application Publication No. 2018-172992

In the drain pump 901 shown in FIG. 5, a part of the drain water that has become a rotating flow flows into the space 922 above the top plate 938 through the gap between the top plate 938 and the housing 910. Since this upper space 922 has no wall in the radial direction and is open, the drain water that has flowed into the upper space 922 does not remain in the upper space 922 but falls from the opening 939 of the upper plate 938. The large-diameter blade 933 turns the flow into a rotating flow again, resulting in a circulating flow indicated by the arrow Fc. The drain water that has flowed into the upper space 922 mixes with air as it flows over the upper plate 938 and falls from the upper plate 938 to generate air bubbles, and these air bubbles ride the circulating flow, producing noise. I had left it behind.

Therefore, an object of the present invention is to provide a drainage pump that can effectively reduce noise.

In order to solve the above problems, a drainage pump according to the present invention includes a housing and a rotary vane rotatably housed in the housing, and the rotary vane has a shaft portion and a shaft portion. a plurality of large-diameter blades extending in a radial direction from the part; a plurality of small-diameter blades connected to a lower end of the large-diameter blade; an annular lower plate that is inserted through the ring, and an annular upper plate that connects the upper ends of the plurality of large-diameter blades and into which the shaft portion is inserted, between the adjacent large-diameter blades; The housing has a cylindrical peripheral wall part, an annular ceiling part connected to the upper end of the peripheral wall part, and an annular ceiling part connected to the inner peripheral edge of the ceiling part. A cylindrical portion extending downward from the periphery.

In the present invention, it is preferable that the lower end of the cylindrical portion is disposed inside the inner peripheral edge of the upper plate when viewed from the axial direction.

According to the present invention, the housing for accommodating the rotary blade includes a cylindrical peripheral wall, an annular ceiling connected to the upper end of the peripheral wall, and an inner peripheral edge of the ceiling, and extends from the inner peripheral edge. It has a cylindrical portion extending downward. Because of this, a torus-shaped space is formed above the upper plate by the upper plate of the rotary blade, the peripheral wall portion, the ceiling portion, and the cylindrical portion of the housing. Therefore, when drain water is scooped up by the rotary blades, the torus-shaped space is filled with drain water and air is expelled, so that it is possible to suppress the drain water flowing on the upper plate of the rotary blades from mixing with air. In addition, since there is a cylindrical part that serves as a wall on the inside of the torus-shaped space in the radial direction, the drain water that flows into the torus-shaped space remains in the space, and a part of the drain water flows between the lower end of the cylindrical part and the rotating blade. It flows out through the gap and falls. Therefore, the area in which the falling drain water comes into contact with the air can be reduced, and the amount of air bubbles generated by mixing with the air when falling can be suppressed. Therefore, noise can be effectively reduced by suppressing the amount of bubbles riding on the circulating flow.

Furthermore, the lower end of the cylindrical portion is arranged inside the inner peripheral edge of the upper plate when viewed from the axial direction, thereby preventing the drain water flowing on the upper plate of the rotary blade from mixing with air. It can be further suppressed. Therefore, the amount of bubbles riding on the circulation flow can be further suppressed, and noise can be reduced more effectively.

FIG. 1 is a sectional view of a drainage pump according to an embodiment of the present invention. It is a figure which shows the rotary vane which the drainage pump of FIG. 1 has. FIG. 2 is a cross-sectional view schematically showing the state of drain water in the drainage pump of FIG. 1. FIG. FIG. 2 is a cross-sectional view schematically showing the state of drain water in a conventional drainage pump. FIG. 3 is a cross-sectional view schematically showing the state of drain water in another conventional drainage pump.

The configuration of a drainage pump according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 3. The drainage pump according to this embodiment is, for example, for discharging drain water accumulated in a drain pan of an indoor unit of an air conditioner to the outside. Of course, the use of this drainage pump is not limited to discharging drain water, but can be used for discharging or pumping various liquids.

FIG. 1 is a cross-sectional view (longitudinal cross-sectional view) along the axial direction of a rotary vane of a drainage pump according to an embodiment of the present invention. FIG. 2 is a diagram showing rotary vanes included in the drainage pump of FIG. 1. FIGS. 2(a) to 2(c) are a perspective view, a plan view, and a front view, respectively. FIG. 3 is a vertical cross-sectional view schematically showing the state of drain water in the drain pump of FIG. 1. In FIG. 3, the area filled with dots indicates drain water, and the area where the dot density is relatively high indicates that the water pressure is comparable to that of the drain water in the discharge pipe 18. Note that in FIGS. 1 and 3, the housing is a cross-sectional view, but the rotating blade is shown as viewed from the front.

As shown in FIG. 1, the drainage pump 1 of this embodiment includes a housing 10, a rotating blade 30, and a drive section 40. In this embodiment, the housing 10 and the rotating blade 30 are made of synthetic resin.

The housing 10 has a bottom wall portion 11, a peripheral wall portion 12, a ceiling portion 13, and a cylindrical portion 15. The bottom wall portion 11 is formed in the shape of an inverted truncated cone. The peripheral wall portion 12 is formed in a cylindrical shape and is connected to the outer peripheral edge of the bottom wall portion 11 . The ceiling portion 13 is formed in the shape of an annular plate, and is connected to the upper end of the peripheral wall portion 12 . An opening 14 is provided in the center of the ceiling portion 13 for introducing air. A cylindrical portion 15 extending downward is connected to an inner circumferential edge 13a defining an opening 14 in the ceiling portion 13. As shown in FIG. A pump chamber 21 is provided inside the housing 10.

A cylindrical suction pipe 17 extending downward is provided at the center of the bottom wall portion 11 . The suction pipe 17 has a suction port 17a facing downward. The peripheral wall portion 12 is provided with a cylindrical discharge pipe 18 extending laterally (to the left in FIG. 1). The discharge pipe 18 has a discharge port 18a facing laterally. In this embodiment, the discharge pipe 18 is formed in a straight line, but is not limited to this. For example, the discharge pipe 18 may be formed in a substantially L-shape or an arc shape with the discharge port 18a facing upward. Suction pipe 17 and discharge pipe 18 are connected to pump chamber 21 .

As shown in FIG. 2, the rotating blade 30 includes a shaft portion 31, a large diameter blade 33, a small diameter blade 34, a lower plate 36, and an upper plate 38. The rotary blade 30 has a plurality of large-diameter blades 33 and small-diameter blades 34 formed in a flat plate shape, and in this embodiment, each blade has four blades. The rotary vane 30 is rotatably housed in the pump chamber 21. The rotating blade 30 is rotated in the direction indicated by an arrow R by the drive unit 40.

The shaft portion 31 is formed in a cylindrical shape. The upper end surface of the shaft portion 31 is provided with a shaft fitting hole 31a into which a rotating shaft of a motor (not shown) included in the drive portion 40 is fitted. The shaft portion 31 is inserted into an opening 14 located inside the ceiling portion 13 of the housing 10 .

The plurality of large-diameter blades 33 extend in the radial direction (radial direction) from the outer circumferential surface of the shaft portion 31 . The plurality of large diameter blades 33 are arranged at equal intervals in the rotation direction. The space between adjacent large-diameter blades 33 is opened laterally.

The plurality of small-diameter blades 34 are connected to the radially inner portion of the lower end of each large-diameter blade 33 . The lower ends of the plurality of small diameter blades 34 are inserted into the suction pipe 17.

The lower plate 36 is formed in an annular shape, and has an opening 37 in the center. The lower plate 36 connects the radially outer portions of the lower ends of the large-diameter blades 33 to each other. A plurality of small-diameter blades 34 are inserted into the opening 37 on the inside of the lower plate 36 .

The upper plate 38 is formed in an annular shape, and has an opening 39 in the center. The upper plate 38 connects the radially outer portions of the upper ends of the large-diameter blades 33 to each other. The shaft portion 31 is inserted into the opening 39 on the inside of the upper plate 38 .

The upper plate 38 forms a torus-shaped upper space 22 above the rotary blade 30 together with the peripheral wall 12, ceiling 13, and cylindrical portion 15 of the housing 10. The upper space 22 is connected to a lower space 23 below the upper plate 38 through a gap 22a between the peripheral wall 12 and the upper plate 38. Further, the upper space 22 is connected to the lower space 23 through a gap 22b between the lower end 15a of the cylindrical portion 15 and the inner peripheral edge 38a defining the opening 39 in the upper plate 38.

In this embodiment, the lower end 15a of the cylindrical portion 15 of the housing 10 is disposed inside the inner peripheral edge 38a of the upper plate 38 when viewed from the axis L direction.

The drive unit 40 includes a motor (not shown) that rotates the rotary blade around the axis L. The drive section 40 is arranged above the ceiling section 13 of the housing 10.

The respective axes of the peripheral wall portion 12, ceiling portion 13, and cylindrical portion 15 of the housing 10, as well as the rotating blade 30, are arranged to coincide with the axis L.

Next, the operation (action) of the drainage pump 1 of this embodiment will be explained.

When the rotary blade 30 is rotated by the drive unit 40, drain water is sucked up into the pump chamber 21 from the suction port 17a. The drain water in the pump chamber 21 is pushed in the direction of arrow R by the large-diameter blade 33, and a centrifugal force is generated radially outward in the lower space 23 below the upper plate 38, resulting in a rotating flow. The drain water flows from the inside in the radial direction to the outside along the large-diameter blade 33 and hits the peripheral wall 12 of the housing 10. Then, when the large-diameter blade 33 passes through the discharge pipe inlet 18b, drain water flows into the discharge pipe inlet 18b, passes through the discharge pipe 18, and is discharged from the discharge port 18a.

When the rotating drain water hits the peripheral wall 12, a portion of the drain water flows into the upper space 22 through the gap 22a between the peripheral wall 12 and the upper plate 38. The drain water that has flowed into the upper space 22 flows radially inward, but the cylindrical portion 15 acts as a wall and is retained within the upper space 22. As a result, the upper space 22 is filled with drain water, and air is expelled from the upper space 22. Therefore, the drain water flowing on the upper plate 38 does not mix with air.

A part of the drain water in the upper space 22 falls into the lower space 23 from the gap 22b between the lower end 15a of the cylindrical portion 15 and the inner peripheral edge 38a of the upper plate 38, and becomes a rotating flow again. By having the cylindrical part 15, the drain water passes through the gap 22b and falls, so compared to a conventional drainage pump without the cylindrical part 15, the area where the falling drain water contacts the air (air-liquid interface S ) becomes smaller. Therefore, when drain water falls, the number of air bubbles that are generated when it mixes with air is reduced.

As described above, according to the drainage pump 1 of the present embodiment, the housing 10 that accommodates the rotary vane 30 has a cylindrical peripheral wall part 12, an annular ceiling part 13 connected to the upper end of the peripheral wall part 12, and a ceiling The cylindrical portion 15 is connected to the inner peripheral edge 13a of the portion 13 and extends downward from the inner peripheral edge 13a. By doing so, a toroidal upper space 22 is formed above the upper plate 38 by the upper plate 38 of the rotating blade 30, the peripheral wall portion 12, the ceiling portion 13, and the cylindrical portion 15 of the housing 10. Therefore, when drain water is scooped up by the rotary blade 30, the upper space 22 is filled with drain water and air is expelled, so that the drain water flowing on the upper plate 38 of the rotary blade 30 is suppressed from mixing with air. can. Furthermore, since the cylindrical portion 15 serving as a wall exists inside the upper space 22 in the radial direction, the drain water that has flowed into the upper space 22 remains in the upper space 22, and a portion of the drain water flows between the lower end 15a of the cylindrical portion 15 and the upper portion. It flows out from the gap 22b between the inner peripheral edge 38a of the plate 38 and falls. Therefore, the area in which the falling drain water comes into contact with the air can be reduced, and the amount of air bubbles generated by mixing with the air when falling can be suppressed. Therefore, noise can be effectively reduced by suppressing the amount of bubbles riding on the circulating flow.

Further, the lower end 15a of the cylindrical portion 15 is arranged inside the inner peripheral edge 38a of the upper plate 38 when viewed from the axis L direction (axial direction). By doing so, the entire upper surface of the upper plate 38 of the rotating blade 30 faces the upper space 22, so that it is possible to further suppress the drain water flowing on the upper plate 38 from mixing with air. Therefore, the amount of bubbles riding on the circulation flow can be further suppressed, and noise can be reduced more effectively.

Although examples of the present invention have been described above, the present invention is not limited to these examples. Additions, deletions, and design changes to the above-mentioned embodiments by those skilled in the art as appropriate, as well as combinations of features of the embodiments as appropriate, are also covered by this invention, as long as they have the gist of the present invention. within the scope of the invention.

DESCRIPTION OF SYMBOLS 1... Drain pump, 10... Housing, 11... Bottom wall part, 12... Peripheral wall part, 13... Ceiling part, 13a... Inner peripheral edge, 14... Opening, 15... Cylindrical part, 15a... Lower end, 17... Suction pipe, 17a... Suction port, 18...Discharge pipe, 18a...Discharge port, 18b...Discharge pipe inlet, 21...Pump chamber, 22...Upper space, 22a, 22b...Gap, 23...Lower space, 30...Rotating vane, 31...Shaft portion, 31a...Shaft fitting hole, 33...Large diameter blade, 34...Small diameter blade, 36...Lower plate, 37...Opening, 38...Upper plate, 38a...Inner peripheral edge, 39...Opening, 40...Drive part, L...Axis line, S...Air-liquid interface

Claims (3)

A drainage pump comprising a housing and a rotary vane rotatably housed in the housing,
The rotary blade includes a shaft portion, a plurality of large diameter blades extending in a radial direction from the shaft portion, a plurality of small diameter blades connected to a lower end of the large diameter blade, and a lower end of the plurality of large diameter blades. an annular lower plate connected to each other and into which the plurality of small-diameter blades are inserted; and an annular upper plate which connects the upper ends of the plurality of large-diameter blades and into which the shaft portion is inserted; and a space between the adjacent large-diameter blades is opened laterally,
The housing includes a cylindrical peripheral wall part, an annular ceiling part connected to an upper end of the peripheral wall part, and a cylindrical part connected to an inner peripheral edge of the ceiling part and extending downward from the inner peripheral edge. death ,
A drainage pump characterized in that the cylindrical portion has a portion whose outer diameter gradually increases upward from the lower end of the cylindrical portion . 2. The drainage pump according to claim 1, wherein the drainage pump is other than one in which the housing has a cylindrical portion extending upward from the inner circumferential edge of the ceiling. The drainage pump according to claim 1 or 2 , wherein a lower end of the cylindrical portion is arranged inside an inner peripheral edge of the upper plate when viewed from the axial direction.

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