Drain pump

Abstract

The drainage pump comprises: a motor and a pump body, the pump body having a housing, a rotating blade and a cover, the upper portion of the housing is open, a suction port is provided at the lower end portion of the housing, and a discharge port for connecting a drainage pipe is provided at the side portion of the housing, the rotating blade is connected to the motor, the cover has a through hole in the center portion and is mounted on the upper end portion of the housing, a pump chamber is divided by the housing and the cover, and a convex portion is provided at the end portion of the discharge outlet in the discharge outlet to prevent return water from the drainage pipe from flowing into the discharge outlet.

Description

Technical Field

[0001] The present invention relates to a drainage pump, and in particular to a drainage pump suitable for discharging the drainage in a drainage pan of water condensed in an indoor heat exchanger of an air conditioner to the outside. Background Art

[0002] As disclosed in Japanese Patent No. 6304990, conventional air conditioners embedded in indoor ceilings are equipped with a drain pan that receives the drain condensed on the surface of the indoor heat exchanger of the air conditioner. The drain in the drain pan is discharged to the outside using a drain pump (discharge pump).

[0003] The drainage pump has a motor, a motor box supporting the motor, and a pump body arranged below the motor box. A suction port is provided at the lower end of the housing of the pump body, and a discharge port is provided at the side of the pump body. A rotary blade that is rotated by the motor is accommodated inside a pump chamber provided in the housing. The rotary blade has a shaft portion connected to the drive shaft of the motor and a plurality of flat plate-shaped large-diameter blades extending radially from the outer periphery of the shaft portion. In addition, a through hole through which the drive shaft of the power supply machine passes is formed in the upper portion of the housing.

[0004] When the motor is driven to rotate the rotary blades at high speed, the drain water accumulated in the drain pan is sucked up from the suction port and flows into the pump chamber, and the drain water in the pump chamber is discharged from the discharge port by the centrifugal force of the rotating rotary blades. Then, the drain water discharged from the discharge port is discharged to the outside through the pipe.

[0005] Technical problem to be solved by the invention

[0006] However, when the discharge of the drainage ends and the rotation of the rotary blades of the drainage pump stops, part of the drainage remaining in the pipe enters the drainage port from the drainage port outlet, and further enters the pump chamber from the drainage port inlet. That is, part of the drainage flows back to the drainage pump. Hereinafter, the backflowing drainage is appropriately referred to as backwater. In this way, when the drainage pump stops and the backwater flows back to the drainage pump, noise may be generated, and countermeasures need to be taken. Summary of the invention

[0007] An object of the present invention is to provide a drainage pump capable of reducing noise generated by backflow when the drainage pump is stopped.

[0008] Technical means for solving technical problems

[0009] In order to solve the above-mentioned technical problems, the drainage pump of the present invention comprises: a motor and a pump body, the pump body having a casing, a rotating blade and a cover, the upper portion of the casing is open, and a suction port is provided at the lower end portion of the casing and a discharge port for connecting a drainage pipe is provided at the side portion of the casing, the rotating blade is connected to the motor, the cover has a through hole in the central portion and is mounted on the upper end portion of the casing, a pump chamber is divided by the casing and the cover, a convex portion is provided at the end portion of the discharge port in the discharge port, the convex portion hinders the return water from the drainage pipe from flowing into the discharge port, and the radial outer portion of the end portion of the discharge port outlet is formed as an end face at a right angle to the axis of the discharge port.

[0010] In the drain pump, the convex portion may be provided at the radially inner portion of the end portion of the discharge port, and may protrude from the radially outer portion of the end portion toward the downstream side during drainage from the pump chamber.

[0011] Alternatively, the convex portion may be provided in a ring shape.

[0012] Furthermore, the convex portion and the radially outer portion may be formed in a stepped shape.

[0013] Furthermore, the convex portion may be formed in a tapered shape whose diameter decreases as it protrudes from the radially outer portion.

[0014] Furthermore, a recessed portion recessed from the radially outer portion toward a side opposite to a protruding direction of the convex portion may be formed between the convex portion and the radially outer portion.

[0015] Effects of the Invention

[0016] According to the present invention, it is possible to provide a drainage pump capable of reducing noise generated by backflow during stop. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a longitudinal sectional view showing a drainage pump according to an embodiment of the present invention.

[0018] Figure 2 This is a cross-sectional view of the shell cut along a plane passing through the center line of the discharge port.

[0019] Figure 3 It is an enlarged cross-sectional view showing a modification 1 of the convex portion at the outlet of the discharge port.

[0020] Figure 4 It is an enlarged cross-sectional view showing a second modification of the convex portion at the outlet of the discharge port.

[0021] Figure 5 It is an enlarged cross-sectional view showing a third modification of the convex portion at the outlet of the discharge port.

[0022] Figure 6 It is an enlarged cross-sectional view showing a modification 4 of the convex portion at the outlet of the discharge port.

[0023] Figure 7 This is an enlarged cross-sectional view showing a state in which the inflow of return water from the drainage pipe to the discharge port is blocked by the convex portion. DETAILED DESCRIPTION

[0024] Hereinafter, the mode for implementing the present invention will be described based on the accompanying drawings. Figure 1 In the embodiment, the drainage pump 10 includes a motor 12 and a pump body 20. The motor 12 is disposed above the pump body 20. A motor box 30 for supporting the motor 12 is disposed between the motor 12 and the pump body 20. The pump body 20 is made of, for example, synthetic resin, and includes a housing 40, a rotary blade 50, and a cover 32.

[0025] The upper portion of the housing 40 is open, and a suction port 42 is provided at the lower end of the housing 40 and a discharge port 46 for connecting the drainage pipe 26 is provided at the side of the housing 40. The suction port 42 is formed into a tubular shape having an opening portion 43 at the lower end. The discharge port 46 has a discharge port inlet 48 and a discharge port outlet 68 that are open to the pump chamber 44, and protrudes toward the side. The discharge port outlet 68 is located at the top of the protruding side of the discharge port 46. In other words, the protruding side of the discharge port 46 is the downstream side of the drainage discharged from the pump chamber 44 when the drainage pump 10 is in operation. The discharge port 46 is arranged radially outside the rotating shaft 50CL of the rotary blade 50 described later. The axis 46CL of the discharge port 46 is arranged in the horizontal direction. In addition, the shaft portion 52 located at the center of the rotary blade 50 described later is positioned on the axis 46CL of the discharge port 46.

[0026] When the drain pump 10 is used, the drain pipe 26 is installed at the drain port 46 for discharging the drain discharged from the drain port 46 to the outside of the pump body 20 to an external drain device or the like. The housing 40 is provided with, for example, a pair of claws (not shown) for fixing the motor box 30. In addition, the drain port 46 is not limited to a structure formed integrally with the housing 40, and may also be a structure formed separately from the housing 40 and assembled to the housing 40.

[0027] like Figure 2As shown, a convex portion 70 that blocks the return water from the drainage pipe 26 from flowing into the discharge outlet 68 is provided at the end of the discharge outlet 68 in the discharge outlet 46. Here, "blocking" means making the return water flowing into the discharge outlet 68 turbulent and reducing the flow rate, and does not mean blocking the return water from flowing into the discharge outlet 68. The convex portion 70 is provided in an annular shape, for example, at the radial inner portion 68A at the end of the discharge outlet 68, and protrudes from the radial outer portion 68B of the end toward the downstream side when draining water from the pump chamber 44. In the example shown in the figure, since the axis 46CL of the discharge outlet 46 extends linearly in the radial direction of the pump chamber 44 in the housing 40, it can also be said that the convex portion 70 protrudes in the direction away from the pump chamber 44. In addition, the convex portion 70 can also be formed intermittently in the circumferential direction.

[0028] The convex portion 70 and the radial outer portion 68B are formed in a step shape, for example. Specifically, the radial outer portion 68B is formed as an end face that is perpendicular to the axis 46CL of the discharge port 46. The convex portion 70 protrudes toward the downstream side when draining water from the pump chamber 44 compared to the radial outer portion 68B. The corner portion 70A on the outer peripheral side of the convex portion 70 is chamfered into a cross-sectional plane shape, for example. This chamfer is a so-called C-face.

[0029] In addition, the shape of the protrusion 70 is not limited to this. Figure 3 In the illustrated modification 1, the convex portion 70 is formed in a tapered shape whose diameter decreases as it protrudes from the radially outer portion 68B. In other words, the outer peripheral surface between the radially inner portion 68A and the radially outer portion 68B is formed by the tapered surface 72 .

[0030] in addition, Figure 4 The modification 2 shown in FIG. Figure 2 In the example, the corner 70A on the outer peripheral side of the protrusion 70 is chamfered into a cross-sectional arc shape. This chamfer is the so-called R-face. In addition, in this specification, "chamfering" includes not only the case where an R-face or C-face is formed by processing an outer corner having an angle, but also the case where an outer corner having an R-face or C-face shape is formed by casting, injection molding, etc. For the sake of convenience, the latter is also expressed as "a structure after the corner is chamfered." Figure 5 In the modification 3 shown, a recessed portion 74 is formed between the convex portion 70 and the radially outer portion 68B, which is recessed from the radially outer portion 68B to the opposite side of the protruding direction of the convex portion 70. The recessed portion 74 is formed in an annular shape, for example. In addition, the depth of the recessed portion 74 corresponds to, for example, the position of the protruding portion 66 in the direction of the axis 46CL of the discharge port 46, and the bottom of the recessed portion 74 corresponds to, for example, the position of the maximum diameter of the protruding portion 66. In addition, the recessed portion 74 may be formed intermittently in the circumferential direction.

[0031] And, in Figure 6 In the modification 4 shown, the recess 74 is formed larger than Figure 5Specifically, the depth of the recess 74 exceeds the position of the protrusion 66 in the direction of the axis 46CL of the discharge port 46, for example. In other words, the bottom of the recess 74 is located at a position farther than the protrusion 66 when viewed from the discharge port outlet 68. In addition, in Modification 4, the width of the recess 74 in the radial direction is formed smaller than that in Modification 3. In addition, the width of the recess 74 in Modification 4 may be equal to that in Modification 3.

[0032] like Figure 1 As shown, a hook-shaped protrusion 66 is provided on the outer periphery of the radially outer portion 68B at the end of the drain outlet 68. The protrusion 66 is embedded in the inner surface of the drain pipe 26 when the drain pipe 26 is connected to the drain outlet 46, and has the function of suppressing drainage from leaking out of the gap between the drain pipe 26 and the drain outlet 68.

[0033] like Figure 3 As shown, a step portion 18 is formed at the upper edge of the inner surface 40A of the housing 40. The step portion 18 extends from the inner surface 40A of the housing 40 toward the radially outer side of the housing 40. A sealing member 34 described later is disposed at the step portion 18.

[0034] like Figure 1 As shown, the rotating blade 50 is connected to the motor 12 and is accommodated in the pump chamber 44. The rotating blade 50 is made of, for example, synthetic resin, and has: a shaft portion 52; a plurality of flat plate-shaped large-diameter blades 60 extending from the outer periphery of the shaft portion 52 in the radial direction of the rotating shaft 50CL (in other words, radially outward); and a plurality of flat plate-shaped small-diameter blades 61 connected to the lower end edges of the large-diameter blades 60 and inserted into the suction port 42. The large-diameter blades 60 are, for example, arranged at equal angles in the circumferential direction. The lower end edges of the large-diameter blades 60 are formed into a cone that is inclined downward on the inner diameter side. Each lower end edge is connected to a disc-shaped annular component 62 having a plurality of fan-shaped openings 58 in the center.

[0035] The large diameter blade 60 of the rotary blade 50 is provided on the shaft portion 52 in such a manner that it is positioned on the front face of the discharge port 46, i.e., on the axis 46CL of the discharge port 46. In addition, the outer peripheral edge of the annular member 62 is located above the lower end of the inner surface 56 of the discharge port 46 and below the axis 46CL of the discharge port 46.

[0036] The shaft portion 52 passes through the through hole 36 and protrudes toward the motor 12. The through hole 36 functions as an air hole formed in the center of the cover 32. The drive shaft of the motor 12 is inserted and fixed into the hole provided along the central axis of the shaft portion 52. A gap is provided between the through hole 36 and the shaft portion 52.

[0037] The water control disk 14 is attached to the upper surface of the shaft portion 52. The water control disk 14 has a function of preventing the blown-out drainage from directly scattering toward the motor 12 even if the drainage is blown out from the through hole 36 of the cover 32.

[0038] The motor case 30 includes a vertically divisible cylinder 22, and houses the motor 12 in the upper portion of the cylinder 22. The cylinder 22 has a side portion formed with a vertically long slit-shaped drainage hole (in other words, an opening for drainage) (not shown).

[0039] like Figure 1 As shown, the cover 32 has a through hole 36 in the center and is mounted on the upper end of the housing 40. Specifically, the cover 32 is formed integrally with the lower end of the cylinder 22 of the motor box 30, for example. In addition, the cover 32 is embedded in the housing 40 in a state of sandwiching the sealing member 34 between the cover 32 and the step portion 18 of the housing 40. The cover 32 is fixed to the housing 40 by being engaged with the motor box 30 by a claw portion (not shown). In the pump body 20, a pump chamber 44 is divided by the housing 40 and the cover 32.

[0040] A drain pan 80 for temporarily storing drain water discharged from air conditioning equipment or the like is disposed below the suction port 42 .

[0041] (effect)

[0042] This embodiment is constructed as described above, and its function will be described below. Figure 1 In the drain pump 10 of the present embodiment, the lower end of the suction port 42 is appropriately arranged so as to be located below the surface Ws of the drain stored in the drain pan 80. Then, when the motor 12 is driven to rotate the rotary blade 50 at a high speed, the drain stored in the drain pan 80 is sucked up from the suction port 42 and discharged from the discharge port 46 via the pump chamber 44. The drain discharged from the discharge port 46 is discharged to an external drain device or the like via the drain pipe 26. The water flow containing bubbles generated in the drain by the rotation of the rotary blade 50 is stirred and obtains centrifugal force in the pump chamber 44 and flows smoothly to the discharge port 46, and is discharged to the outside via the drain pipe 26.

[0043] When the discharge of the drain is completed and the rotation of the rotary blade 50 of the drain pump 10 stops, a portion of the drain remaining in the drain pipe 26 enters the drain port 46 from the drain outlet 68, and further enters the pump chamber 44 from the drain inlet 48. That is, a portion of the drain becomes backflow and flows back to the drain pump 10. In this embodiment, as shown in FIG. Figure 7As shown in FIG. 1 , a convex portion 70 is provided at the end of the discharge outlet 68 in the discharge outlet 46 to prevent the return water from the drain pipe 26 from flowing into the discharge outlet 68. Specifically, since a space is formed between the outer peripheral side of the convex portion 70 and the drain pipe 26, a part of the return water enters the space, causing flow disturbance, and preventing the flow into the discharge outlet 68, thereby causing pressure loss and reducing the flow rate. As a result, the return water flows from the discharge outlet 68 into the discharge outlet 46 in a state where the kinetic energy is reduced compared to a case where the convex portion 70 is not provided at the discharge outlet 68.

[0044] This is Figures 3 to 5 The same is true for each of the modified examples shown. Figure 3 In the modified example 1 shown in the figure, the convex portion 70 is formed in a tapered shape with a decreasing diameter as it protrudes from the radially outer portion 68B, and the convex portion 70 is formed in a stepped shape compared to the radially outer portion 68B. Figure 2 The structure reduces the kinetic energy of the return water less. Figure 5 Modification 3 and Figure 6 The variation 4 shown is Figure 2 When comparing the modification 3 and the modification 4, the kinetic energy of the return water is reduced more because the recess 74 is deeper and the width of the recess 74 in the radial direction is smaller in the modification 4. Therefore, the kinetic energy of the return water is reduced more.

[0045] As described above, according to the present embodiment, the convex portion 70 reduces the flow velocity of the return water and reduces the kinetic energy, thereby reducing the noise generated when the return water flows back to the drain pump 10 .

[0046] [Other embodiments]

[0047] As mentioned above, an example of the embodiment of the present invention has been described, but the embodiment of the present invention is not limited to the above, and it is needless to say that various modifications other than the above are possible within the scope not departing from the gist of the present invention.

[0048] In the above embodiment, the projection 70 is provided on the radially inner portion 68A of the discharge port outlet 68 . However, the radial position of the projection 70 is not limited thereto, and any structure may be used as long as it can prevent the return water from flowing into the discharge port outlet 68 .

[0049] The entirety of the invention of Japanese Patent Application No. 2020-30956 filed on February 26, 2020 is incorporated into this specification by reference.

[0050] All documents, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated herein by reference.

Claims

1. A drainage pump, comprising: a motor and a pump body, the pump body having a housing, a rotating blade and a cover, the upper portion of the housing is open, a suction port is provided at the lower end of the housing, and a discharge port for connecting a drainage pipe is provided at the side of the housing, the rotating blade is connected to the motor, the cover has a through hole in the center and is mounted on the upper end of the housing, a pump chamber is divided by the housing and the cover, wherein: A convex portion is provided at the end of the discharge outlet of the discharge outlet, and the convex portion prevents return water from the drainage pipe from flowing into the discharge outlet. The radially outer portion of the end portion of the discharge port outlet is formed as an end surface that is perpendicular to the axis of the discharge port.

2. The drainage pump according to claim 1, wherein: The convex portion is provided at a radially inner portion of an end portion of the discharge port, and projects from the radially outer portion of the end portion toward a downstream side when water is discharged from the pump chamber.

3. The drainage pump according to claim 2, wherein: The convex portion is arranged in a ring shape.

4. The drainage pump according to claim 2, wherein: The convex portion and the radially outer portion are formed in a stepped shape.

5. The drainage pump according to claim 3, wherein: The convex portion is formed in a tapered shape whose diameter decreases as it protrudes from the radially outer portion.

6. The drainage pump according to claim 2 or 3, wherein: A recessed portion that is recessed from the radially outer portion toward a side opposite to a protruding direction of the convex portion is formed between the convex portion and the radially outer portion.

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