WO2019106991A1

WO2019106991A1 - Drain pump

Info

Publication number: WO2019106991A1
Application number: PCT/JP2018/038471
Authority: WO
Inventors: 克司佐藤; 友也加藤; 真聖杉野
Original assignee: 株式会社不二工機
Priority date: 2017-12-01
Filing date: 2018-10-16
Publication date: 2019-06-06
Also published as: JP2019100253A

Abstract

[Problem] To provide a drain pump wherein noise caused by a variation in the pressure of drain water within a pump chamber is suppressed to improve quietness during operation. [Solution] A drain pump 1 has a rotating blade 30 accommodated in a pump chamber 25 defined by a housing 10 and a cover 20. The housing 10 has: a body section 11 in which the rotating blade 30 is disposed and which has a bottom wall section 12 and a peripheral wall section 13; a suction pipe 16 extending downward from the body section 11; and a discharge pipe 18 provided on a side of the body section 11. A discharge pipe inlet 15 is provided in the inner peripheral surface 14 of the peripheral wall section 13 of the body section 11, and the discharge pipe inlet 15 has a vertically long elliptical shape.

Description

Drainage pump

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a drainage pump which sucks in water from a suction port by a rotary blade and discharges the water from a discharge port. In particular, the present invention relates to a drainage pump suitable for achieving quietness during operation.

The air conditioner installed on the ceiling of the room has a drain pan for receiving the drain water condensed on the surface of the indoor heat exchanger, and a drainage pump (drain pump) for discharging the drain water in the drain pan.

An example of the conventional drainage pump described in Patent Document 1 is shown in FIG. The conventional drainage pump 900 has a motor 910 and a pump body 930 attached to the motor 910 via a bracket 920. The pump body 930 has a housing 940 open at the top, a cover 932 fitted to the top opening of the housing 940, and a rotary blade 950 connected to the motor 910.

The housing 940 includes a suction pipe 942 having a suction port 943 facing downward, a pump chamber 944 formed in an internal space defined (partitioned) by the housing 940 and the cover 932, and a discharge port 946 facing laterally. And a discharge pipe 945. A discharge pipe inlet 946a is opened in an inner circumferential surface 940a of the housing 940.

The rotary blade 950 includes a shaft portion 952, a plurality of large diameter blades 960, a plurality of intermediate blades 960a, an annular portion 962, and a plurality of small diameter blades 954. The shaft portion 952 is coupled to the drive shaft 912 of the motor 910. The plurality of large diameter blades 960 are formed in a flat plate shape, and are disposed so as to extend in the radial direction from the shaft portion 952. The plurality of intermediate blades 960 a are formed in a flat plate shape, extend in the radial direction, and are arranged alternately with the large diameter blades 960 in the circumferential direction. The annular portion 962 has an inverted frusto-conical shape along the lower side tapered portions of the large diameter blades 960 and the middle blade 960a, and an opening 963 is provided at the center. The plurality of small diameter blades 954 are formed in a flat plate shape, and are connected to the lower end edge of each large diameter blade 960 through the inside of the opening 963. In the rotary blade 950, a large diameter blade 960, an intermediate blade 960 a and an annular portion 962 are disposed in the pump chamber 944, and a small diameter blade 954 is inserted into the suction pipe 942.

JP, 2013-64396, A

FIG. 7 is a plan view schematically showing the flow and pressure of drain water in the pump chamber 944. As shown in FIG. In the drainage pump 900, drain water sucked up from the suction port 943 into the pump chamber 944 is pushed in the rotational direction R by the large diameter blades 960 and the middle blades 960a, and a centrifugal force is generated. As a result, the drain water flows radially inward from the inside in the radial direction along the large diameter blades 960 and the middle blades 960 a and strikes the inner circumferential surface 940 a of the housing 940. Then, when the large diameter blades 960 and the intermediate blades 960a pass through the discharge pipe inlet 946a, drain water flows into the discharge pipe inlet 946a. At this time, in the pump chamber 944, the pressure P of the drain water is generated at the portion surrounded by the inner circumferential surface 940a of the housing 940, but the drain water changes to the pressure P 'near the discharge pipe inlet 946a. Such a change in the pressure of the drain water may disturb the flow of the drain water and cause noise.

The present invention has been made in view of the above problems, and an object thereof is to provide a drainage pump capable of suppressing the noise caused by the change in the pressure of drain water in the pump chamber to achieve quietness during operation. It is to provide.

In order to solve the above problems, a drainage pump according to the present invention is a drainage pump having a rotary vane rotated by a motor, and a housing accommodating the rotary vane, wherein the rotary vane is the one of the motor. A shaft portion attached to a drive shaft, a plurality of large diameter blades extending in a radial direction from the shaft portion, a plurality of small diameter blades connected to lower ends of the plurality of large diameter blades, and a lower end of the plurality of large diameter blades And an annular portion provided at the center with an opening through which the plurality of small diameter blades are inserted, and the housing is provided with a main body portion on which the rotary vanes are disposed inside, and a lower portion from the main body portion And a discharge pipe provided on the side portion of the main body, and an inlet to the discharge pipe is provided at a position on the inner peripheral surface of the main body facing the large diameter blades , Said inlet has a longitudinal shape And said that you are.

In the present invention, the inlet preferably has an oval shape, a rectangular shape, or a rounded square shape.

In the present invention, the rotary vanes have a plurality of auxiliary vanes disposed between the adjacent large-diameter vanes, and the inlet is formed by the large-diameter vanes and the auxiliary vanes on the inner peripheral surface of the main body. It is preferable to provide in the location which opposes.

According to the present invention, the inlet to the discharge pipe is provided at a position facing the large diameter blade on the inner peripheral surface of the main body of the housing, and the inlet has a vertically elongated shape. Since it did in this way, compared with the structure to which the entrance to a discharge pipe has a regular circle shape, square shape and horizontal shape which become the same opening area as the said longitudinal shape, a blade part is maintained, maintaining discharge amount. The time it takes to pass through this entrance can be made shorter. Therefore, since the time for which the pressure of drain water changes can be shortened more, the noise accompanying the pressure change of drain water can be suppressed, and the quietness at the time of operation can be aimed at.

It is a figure showing a drainage pump concerning one example of the present invention. FIG. 2 is a cross-sectional view taken along the line XX in FIG. It is a figure which shows the shape of a discharge pipe inlet typically. It is a figure which shows the structure of the Example of this invention, and a comparative example. It is a figure which shows typically the sound which arises in the Example of this invention, and a comparative example. It is a figure which shows the conventional drainage pump. It is a figure which shows typically the pressure of the drain water in the pump chamber in the drainage pump of FIG.

Hereinafter, the configuration of a drainage pump according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3. The drainage pump of the present 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 application of this drainage pump is not limited to drain water discharge, and can be used for discharge and pumping of various liquids.

FIG. 1 is a view showing a drainage pump according to an embodiment of the present invention, and in detail, is a front view including a partial cross-sectional view of a lower portion of the drainage pump taken along a plane passing through an axis of a discharge pipe. The inside of the lower right circle in FIG. 1 is a view of the discharge pipe inlet as viewed from the axial direction of the discharge pipe. FIG. 2 is a cross-sectional view taken along the line XX in FIG. The XX line coincides with the axis of the discharge tube. FIG. 3 is a view schematically showing the shape of the discharge pipe inlet, and FIG. 3 (a) shows the shape of the discharge pipe inlet according to the embodiment of the present invention, and FIGS. 3 (b) and 3 (c) are The shape of the discharge pipe inlet of the modification of invention is shown, and FIG.3 (d) shows the shape of the discharge pipe inlet of the conventional drainage pump.

As shown in FIG. 1, the drainage pump 1 of the present embodiment has a housing 10, a cover 20, rotating blades 30, and a motor 40. In the present embodiment, the housing 10, the cover 20 and the rotary vanes 30 are made of synthetic resin.

The housing 10 integrally includes a main body portion 11, a suction pipe 16, and a discharge pipe 18. The main body portion 11 has a bottom wall portion 12 having an inverted truncated cone shape, and a peripheral wall portion 13 continuously connected to the outer peripheral edge of the bottom wall portion 12. The suction pipe 16 extends downward from the center of the bottom wall 12 and has a suction port 17 directed downward. The discharge pipe 18 extends laterally (rightward in FIG. 1) from the peripheral wall portion 13 and has a discharge port 19 directed to the side. In the present embodiment, the discharge pipe 18 linearly extends laterally, but is not limited thereto. For example, the discharge port may be formed in a substantially L shape or a circular arc shape facing upward, as long as it is provided on the side portion of the main body portion 11.

A discharge pipe inlet 15 serving as an inlet to the discharge pipe 18 is provided on the inner circumferential surface 14 of the peripheral wall 13 of the main body 11. The discharge pipe inlet 15 has a vertically long oval shape. That is, the discharge pipe inlet 15 is provided in the peripheral wall 13 so that the minor axis a is along the horizontal direction and the major axis b is along the vertical direction.

In the present embodiment, the discharge pipe inlet 15 has a vertically long oval shape, but may have a vertically long shape such as a vertically long rectangular shape or a vertically long rounded square shape. By adopting the vertically elongated shape, the length in the lateral direction (the circumferential direction of the peripheral wall portion 13) can be shortened as compared with a regular circular shape, a square shape, or a horizontally elongated shape having the same opening area. FIGS. 3 (a) to 3 (d) schematically show longitudinally elongated oval shapes, rectangular shapes, rounded square shapes, and conventional regular circular discharge pipe inlets.

The housing 10 has a space in which a rotary vane 30 described later is disposed, and the pump chamber 25 is formed (defined) by surrounding the space together with the cover 20.

The cover 20 has a substantially cylindrical shape, and the lower end portion thereof is fitted with the upper opening of the main body 11 of the housing 10 and fixedly attached to the housing 10 by a snap fit mechanism (not shown). A bracket 22 is attached to an upper end portion of the cover 20 via a locking portion 21. The bracket 22 is provided with a mounting portion 23 for mounting the drainage pump 1 to another device.

The rotary vanes 30 are rotatably accommodated in the pump chamber 25. The rotary blade 30 has a shaft portion 31, a large diameter blade 33, a small diameter blade 34, an auxiliary blade 35, and an annular portion 36. The rotary vane 30 has a plurality of large diameter vanes 33, small diameter vanes 34 and auxiliary vanes 35 formed in a substantially flat plate shape, and has four pieces each in the present embodiment. A configuration in which the auxiliary blade 35 is omitted may be adopted.

The shaft portion 31 is formed in a cylindrical shape, and an attachment hole 32 in which a drive shaft 41 of a motor 40 described later is fitted is provided at the upper end portion. The plurality of large-diameter blades 33 extend in the radial direction (radial direction) from the outer peripheral surface of the shaft portion 31. 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 auxiliary blades 35 are disposed between the circumferentially adjacent large diameter blades 33 and extend in the radial direction. The annular portion 36 has an inverted truncated cone shape and is provided with an opening 37 at its center. The annular portion 36 connects the tapered portions at the lower ends of the large diameter blades 33 and the auxiliary blades 35 to each other. The large diameter vanes 33 and the auxiliary vanes 35 are disposed in the pump chamber 25 such that their radially outer end faces the inner circumferential surface 14 of the peripheral wall 13 of the housing 10. The small diameter vanes 34 pass through the opening 37 of the annular portion 36 and are inserted into the suction pipe 16.

The motor 40 is housed in the cover 20. The shaft portion 31 of the rotary blade 30 is inserted through the through hole 24 provided at the center of the cover 20, and the drive shaft 41 of the motor 40 is fitted in the mounting hole 32 of the shaft portion 31.

Next, the operation (action) of the drainage pump 1 of the present embodiment will be described in comparison with a comparative example in which the discharge port inlet is in the shape of a true circle.

FIG. 4A is a view showing the shape of the discharge pipe inlet 15 of this embodiment. FIG. 4 (b) is a partial cross-sectional view schematically showing a central angle θ1 corresponding to the lateral length of the discharge pipe inlet 15 of this embodiment. FIG.4 (c) is a fragmentary sectional view which shows typically a mode that the large diameter blade | wing 33 and the auxiliary blade | wing 35 pass the discharge pipe inlet 15 of a present Example. FIG. 4D is a view showing the shape of the discharge pipe inlet 115 of the comparative example. FIG. 4E is a partial cross-sectional view schematically showing a central angle θ2 corresponding to the lateral length of the discharge pipe inlet 115 of the comparative example. FIG. 4F is a partial cross-sectional view schematically showing how the large diameter vanes 33 and the auxiliary vanes 35 pass through the discharge pipe inlet 15 of the comparative example. In FIG. 4 (d) to (f) showing the comparative example, the same reference numerals are given to the same components as the present embodiment, and the description will be omitted.

When the rotary vanes 30 are rotated by the drive shaft 41 of the motor 40, drain water is sucked into the pump chamber 25 from the suction port 17. The drain water in the pump chamber 25 is pushed in the rotational direction by the large diameter vanes 33 and the auxiliary vanes 35 to generate a centrifugal force. As a result, the drain water flows from the inside to the outside in the radial direction along the large diameter blades 33 and the auxiliary blades 35 and strikes the inner circumferential surface 14 of the peripheral wall 13 of the housing 10. Then, when the large diameter vanes 33 and the auxiliary vanes 35 pass through the discharge pipe inlet 15, drain water flows into the discharge pipe inlet 15. At this time, in the pump chamber 25, the pressure of the drain water near the discharge pipe inlet 15 changes with respect to the pressure of the drain water at a portion surrounded by the inner circumferential surface 14. Due to the change in the pressure of the drain water, the flow of the drain water is disturbed and a sound is emitted.

Here, in the present embodiment, the discharge pipe inlet 15 has a vertically long elliptical shape, and the lateral length (short diameter) is a. In the comparative example, the discharge pipe inlet 115 has a circular shape, and the lateral length is c. When the discharge pipe inlet 15 of the present embodiment and the discharge pipe inlet 115 of the comparative example have the same opening area, a <c. Therefore, assuming that the central angle corresponding to the lateral length of the discharge pipe inlet 15 of the present embodiment is θ1, and the central angle corresponding to the lateral length c of the discharge pipe inlet 115 of the comparative example is θ2, θ1 < It becomes θ2. And, in the embodiment and the comparative example, when the rotational speed (angular velocity) of the rotary vanes 30 is the same, the present embodiment is implemented from time T2 when the large diameter vane 33 and the auxiliary vane 35 pass the discharge pipe inlet 115 of the comparative example. The time T1 for passing through the discharge pipe inlet 15 of the example is shorter. From this, in the present embodiment, the time for which the sound is generated when the large diameter blade 33 (or the auxiliary blade 35) passes through the discharge pipe inlet 15 is shorter than the time for the sound to be generated in the comparative example.

5 (a) and 5 (b) show four large-diameter blades 33 (large-diameter blades [1] to [4]) and four auxiliary blades 35 (auxiliary blades [in the present embodiment and the comparative example]. 1] to [4] are diagrams schematically showing a sound generated when passing through the discharge pipe inlet and a synthetic sound in which the sounds generated by the respective blades overlap. As shown in FIG. 5 (b), in the comparative example, the rear end of the sound generated by one blade and the front end of the sound generated by the next blade overlap. On the other hand, as shown in FIG. 5A, in the present embodiment, it is possible to avoid that the rear end of the sound generated by one blade and the front end of the sound generated by the next blade overlap. Or, the time during which the sounds overlap can be made shorter. Therefore, the present embodiment can make the sound smaller than that of the comparative example.

As mentioned above, according to the drainage pump 1 which concerns on a present Example, the discharge pipe inlet 15 is provided in the internal peripheral surface 14 of the surrounding wall part 13 of the main-body part 11 which the housing 10 has, and the discharge pipe inlet 15 is a longitudinally long ellipse. It has a shape. Since it did in this way, compared with the structure which the discharge pipe inlet 15 has the same circular open area and square shape, and a laterally long shape which becomes it, a large diameter blade | wing and an auxiliary blade | wing are maintained, maintaining discharge amount. The time it takes to pass through this entrance can be made shorter. Therefore, since the time for which the pressure of drain water changes can be shortened more, the noise accompanying the pressure change of drain water can be suppressed, and the quietness at the time of operation can be aimed at.

Although the embodiments of the present invention have been described above, the present invention is not limited to these examples. Those skilled in the art may appropriately add, delete, or change the design elements from the above-described embodiment, or appropriately combine the features of the embodiment, as long as the gist of the present invention is included. Included in the scope of the invention.

DESCRIPTION OF SYMBOLS 1 ... drain pump, 10 ... housing, 11 ... main body part, 12 ... bottom wall part, 13 ... peripheral wall part, 14 ... inner peripheral surface, 15 ... discharge pipe inlet, 16 ... suction pipe, 17 ... suction port, 18 ... discharge Pipe 19 19 discharge port 20 cover 21 locking portion 22 bracket 23 mounting portion 24 through hole 25 pump chamber 30 rotary blade 31 shaft portion 32 mounting hole 33: large diameter blade 34: small diameter blade 35: auxiliary blade 36: annular portion 37: opening 40: motor 41: drive shaft

Claims

A drainage pump comprising: a rotating blade rotated by a motor; and a housing accommodating the rotating blade,
The rotary blade includes: a shaft portion attached to a drive shaft of the motor; a plurality of large diameter blades extending in a radial direction from the shaft portion; and a plurality of small diameter blades connected to lower ends of the plurality of large diameter blades. And an annular portion having a central opening provided for connecting the lower ends of the plurality of large-diameter blades and through which the plurality of small-diameter blades are inserted.
The housing includes a main body portion in which the rotary vanes are disposed inside, a suction pipe extending downward from the main body portion, and a discharge pipe provided on a side portion of the main body portion.
An inlet to the discharge pipe is provided at a position on the inner peripheral surface of the main body opposite to the large diameter blade,
The said inlet has a longitudinally long shape, The drainage pump characterized by the above-mentioned.
The drainage pump according to claim 1, wherein the inlet has an oval shape, a rectangular shape, or a rounded square shape.
The rotary vanes have a plurality of auxiliary vanes disposed between the adjacent large diameter vanes,
The said inlet is provided in the location facing the said large diameter blade | wing and the said auxiliary blade | wing in the internal peripheral surface of the said main-body part, The drainage pump of Claim 1 or Claim 2 characterized by the above-mentioned.