Drain pump

Abstract

A drain pump is provided that can reduce the amount of condensate remaining in the drain pan. The drain pump (1) has: a housing (10), a rotating vane (20) housed in the housing (10), and an electric motor (30) having a drive shaft (32) connected to the rotating vane (20). The housing (10) has a cylindrical suction pipe (12) extending in the vertical direction. Furthermore, a downward-facing suction port (12a) and an annular concave surface (12b) surrounding the suction port (12a) are provided at the lower end (12c) of the suction pipe (12).

Description

Technical Field

[0001] The present invention relates to a drain pump for draining condensate, for example, from an air conditioner. Background Technology

[0002] Patent Document 1 discloses an example of a conventional drainage pump. The drainage pump of Patent Document 1 has: a housing and rotating vanes housed within the housing. The housing has a suction pipe extending in a vertical direction. A downward-facing suction port is provided at the lower end of the suction pipe.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 5422277

[0006] The technical problem that the invention aims to solve

[0007] The drain pump draws up condensate that has accumulated in the drain pan through its suction inlet. However, because a gap needs to be created between the suction inlet and the drain pan, the drain pump cannot draw up all the condensate. As a result, condensate remains in the drain pan, potentially forming a slimy residue. Summary of the Invention

[0008] Therefore, the object of the present invention is to provide a drain pump that can reduce the amount of condensate remaining in the drain pan.

[0009] Technical means for solving technical problems

[0010] The inventors of this application, focusing on the suction pipe of a drain pump, discovered that when the pump reaches a state where it can no longer draw condensate from the drain pan during the condensate drainage process—that is, when the drawn-up condensate does not fall but remains inside the casing (hereinafter referred to as the "equilibrium state")—the condensate rises from its surface to the lower end of the suction pipe due to surface tension, causing the condensate level to become lower than the lower end of the suction pipe. Therefore, the inventors of this application carefully studied the shape of the suction pipe and conceived of this invention.

[0011] To solve the above-mentioned technical problems, the drainage pump of the present invention has: a housing; a rotating blade housed in the housing; and an electric motor having a drive shaft connected to the rotating blade. The housing has a cylindrical suction pipe extending in a vertical direction, with a suction port and an annular concave surface at the lower end of the suction pipe, the suction port facing downwards, and the concave surface surrounding the suction port.

[0012] In this invention, it is preferred that the radial width (wall thickness of the inhalation tube) at the lower end of the inhalation tube is 2.5 mm or more and 8 mm or less.

[0013] The effects of the invention

[0014] The drain pump of the present invention has a cylindrical suction pipe extending vertically. Furthermore, a downward-facing suction port and an annular concave surface surrounding the suction port are provided at the lower end of the suction pipe. As a result, the drain pump exerts high surface tension on the condensate through the concave surface, causing the condensate to rise to a higher position. Therefore, the drain pump can draw up condensate until the water level is lower, effectively reducing the amount of condensate remaining in the drain pan. Attached Figure Description

[0015] Figure 1 This is a diagram illustrating a drainage pump according to an embodiment of the present invention.

[0016] Figure 2 yes Figure 1 An enlarged sectional view of the lower end of the suction pipe of the drainage pump.

[0017] Figure 3 It is a graph showing the water level position relative to the lower end of the suction pipe in a drain pump in equilibrium. Detailed Implementation

[0018] The following is for reference Figure 1 , Figure 2 A drainage pump according to an embodiment of the present invention will be described.

[0019] Figure 1 This is a diagram illustrating a drainage pump according to an embodiment of the present invention. Figure 1 (a) is a cross-sectional view of the drainage pump. Figure 1 In (a), only the outer casing and the motor housing are shown in cross-section. Figure 1 (b) is a diagram showing the inhalation tube from below. Figure 2 yes Figure 1 An enlarged sectional view of the lower end of the suction pipe of the drainage pump.

[0020] The drain pump in this embodiment is used to discharge condensate, for example, from the drain pan of the indoor unit of an air conditioner to the outside. The application of this drain pump is not limited to condensate drainage. The drain pump can be used for draining, sucking up, etc., various liquids from containers.

[0021] like Figure 1 As shown, the drainage pump 1 of this embodiment includes: a housing 10, a rotating vane 20, a motor 30, and a motor housing 40. The housing 10, the rotating vane 20, and the motor housing 40 are made of synthetic resin.

[0022] The outer casing 10 has a main body 11 that is approximately inverted frustum-shaped. A suction pipe 12 extending downwards is provided in the main body 11. The suction pipe 12 has a cylindrical shape that extends linearly in the vertical direction. A downward-facing suction port 12a is provided at the lower end 12c of the suction pipe 12. An annular concave surface 12b is provided at the lower end 12c of the suction pipe 12, surrounding the suction port 12a. A discharge pipe 13 extending laterally is provided in the main body 11. The discharge pipe 13 has a laterally facing discharge port 13a. The discharge pipe 13 has a cylindrical shape that extends linearly in the horizontal direction. Alternatively, the discharge pipe 13 may have an approximately L-shaped or arc-shaped discharge port 13a facing upwards. The suction pipe 12 and the discharge pipe 13 are connected to a pump chamber 14 located inside the main body 11.

[0023] In the lower end 12c of the suction pipe 12, the outer diameter D of the suction pipe 12 is preferably 16 mm or more and 25 mm or less. Furthermore, the radial width RT (wall thickness of the suction pipe 12) at the lower end of the suction pipe 12 is preferably 2.5 mm or more and 8 mm or less. Width RT is also the width of the concave surface 12b. When the outer diameter D is less than 16 mm, the width of the concave surface 12b cannot be sufficiently ensured, and due to surface tension, the height H of the portion Wa rising from the water surface Ws in the condensate W becomes smaller. When the outer diameter D is greater than 25 mm, the suction pipe 12 interferes with the condensate collection basin provided in the drain pan. Furthermore, by setting the outer diameter D to 16 mm or more and 25 mm or less, the drain pump 1 can ensure the height H of the portion Wa of the condensate W through surface tension and prevent interference between the suction pipe 12 and the collection basin of the drain pan, thereby more effectively reducing the amount of condensate W remaining in the drain pan. Additionally, when the width RT is less than 2.5 mm, the drain pump cannot obtain the high surface tension based on the concave surface 12b. When the width RT is greater than 8mm, the outer diameter D becomes larger, which may lead to the aforementioned interference.

[0024] The rotating blade 20 has a shaft portion 21, a large-diameter blade portion 22, and a small-diameter blade portion 23. The shaft portion 21 is cylindrical. The large-diameter blade portion 22 has a plurality of flat, large-diameter blades (not shown) extending radially from the shaft portion 21. The large-diameter blade portion 22 has a cylindrical ring 22a connecting the tips of the plurality of large-diameter blades and an annular lower plate 22b whose outer periphery is connected to the lower end of the ring 22a. The large-diameter blade portion 22 is disposed in the pump chamber 14. The small-diameter blade portion 23 has a plurality of flat, small-diameter blades 23a. The plurality of small-diameter blades 23a extend downward from the lower ends of the plurality of large-diameter blades through the inside of the lower plate 22b. The small-diameter blade portion 23 is disposed inside the suction pipe 12.

[0025] The electric motor 30 is positioned above the housing 10. The electric motor 30 has an electric motor body 31 and a drive shaft 32 extending downward from the electric motor body 31. The drive shaft 32 is connected to the shaft portion 21 of the rotating blade 20.

[0026] The motor housing 40 is mounted to the outer casing 10 via a snap-fit ​​mechanism. The motor housing 40 has a lower casing 50 and an upper casing 60.

[0027] The lower housing 50 has a bottom wall portion 51, a peripheral wall portion 54, and a motor support portion 56.

[0028] The bottom wall portion 51 has a circular plate shape. The bottom wall portion 51 closes the upper opening of the main body portion 11 of the outer casing 10. The bottom wall portion 51 and the main body portion 11 together divide the pump chamber 14. A shaft hole 51a is provided in the center of the bottom wall portion 51. The shaft portion 21 of the rotating blade 20 is arranged in the shaft hole 51a.

[0029] The peripheral wall portion 54 has a cylindrical shape. The lower end of the peripheral wall portion 54 is connected to the bottom wall portion 51. The peripheral wall portion 54 extends upward from the bottom wall portion 51. An electric motor support portion 56 is connected to the upper end of the peripheral wall portion 54.

[0030] The upper housing 60 is mounted to the motor support 56 via a snap-fit ​​mechanism. The upper housing 60 covers the upper part of the motor 30. The motor housing 40 houses the motor 30 between the motor support 56 and the upper housing 60. A portion of the motor 30, including its wiring, is located on the outside of the motor housing 40.

[0031] As described above, the drain pump 1 of this embodiment has a cylindrical suction pipe 12 extending vertically. Furthermore, at the lower end 12c of the suction pipe 12, there is a downward-facing suction port 12a and an annular concave surface 12b surrounding the suction port 12a. Therefore, the drain pump 1 can use surface tension to lift the condensate W to a higher position. Thus, by drawing up the condensate W until the water level is lower, the amount of condensate W remaining in the drain pan can be effectively reduced.

[0032] The embodiments of the present invention have been described above, but the present invention is not limited to the structure of the embodiments. Embodiments obtained by adding, deleting, or modifying the constituent elements of the foregoing embodiments appropriately, or by appropriately combining the features of the embodiments, as long as they possess the spirit of the present invention, are included within the scope of the present invention.

[0033] The inventors of this application used Embodiment 1 and Comparative Examples 1 and 2 of the drain pump of the present invention to measure the water level of the condensate relative to the lower end of the suction pipe in an equilibrium state, thereby verifying the effect of the present invention.

[0034] Example 1 has the structure of the drain pump 1 described above. In Example 1, the outer diameter D at the lower end of the suction pipe is 20.0 mm. The shape around the suction port is a concave annular surface, and the radial width RT at the lower end of the suction pipe is 4.5 mm.

[0035] In Comparative Example 1, the outer diameter D and width RT at the lower end of the inhalation tube are the same as in Example 1. However, in Comparative Example 1, the shape around the inhalation port is a circular plane, which is different from that in Example 1. Comparative Example 1 has the same structure as Example 1 except for the inhalation tube.

[0036] In Comparative Example 2, the outer diameter D at the lower end of the suction tube is 16.0 mm, and the shape around the suction port is a circular plane. Furthermore, in Comparative Example 2, the radial width RT at the lower end of the suction tube is 2.5 mm, which is narrower than the width RT of Comparative Example 1. Comparative Example 2 has the same structure as Example 1, except for the suction tube.

[0037] The inventors of this application used Example 1 and Comparative Examples 1 and 2 to discharge condensate W from the drain pan and measured the water level position of the condensate W relative to the lower end of the suction pipe when it reached equilibrium. The inventors of this application measured the water level position three times in each of Example 1 and Comparative Examples 1 and 2 and calculated the average value. Table 1 shows the structure of the suction pipe and the measurement results for Example 1 and Comparative Examples 1 and 2. Figure 3 This indicates the measurement result. Figure 3 It is a graph showing the average water level position relative to the lower end of the suction pipe in a drain pump in equilibrium.

[0038] [Table 1]

[0039]

[0040] Unit: mm

[0041] According to the measurement results of Comparative Examples 1 and 2, increasing the width of the plane around the suction inlet can lower the condensate water level. Furthermore, according to the measurement results of Example 1 and Comparative Example 1, changing the shape around the suction inlet from a plane to a concave surface can further lower the condensate water level. That is, in the drain pump, by making the shape around the suction inlet a concave annular shape, compared to a structure using a flat annular shape, the condensate water level can be lowered.

[0042] Therefore, it can be seen that the effect of the present invention is significant even in verification using real machines.

[0043] Symbol Explanation

[0044] 1…drain pump, 11…main body, 12…suction pipe, 12a…suction port, 12b…concave surface, 12c…lower end, 13…discharge pipe, 13a…discharge port, 14…pump chamber, 10…outer shell, 20…rotating blade, 21…shaft, 22…large diameter blade section, 22a…ring, 22b…lower plate, 23…small diameter blade section, 23a…small diameter blade, 30…motor, 31…motor body, 32…drive shaft, 40…motor housing, 50…lower housing, 51…bottom wall, 51a…shaft hole, 54…peripheral wall, 56…motor support, 60…upper housing, W…condensate, Ws…water surface, Wa…part of condensate standing upright from the surface.

Claims

1. A drainage pump, characterized in that, It comprises: a housing; a rotating blade housed within the housing; and an electric motor having a drive shaft connected to the rotating blade. The outer casing has a cylindrical suction tube that extends vertically. The suction tube has an inlet and an annular concave surface. The inlet faces downwards, and the concave surface surrounds the inlet. The inlet is located at the lower end of the inlet tube. The concave surface is formed on the lower end face of the suction tube. The concave surface has a deepest part, an inner edge, and an outer edge. The deepest part is positioned higher than the inner edge and the outer edge.

2. The drainage pump according to claim 1, characterized in that, The radial wall thickness at the lower end of the inhalation tube is more than 2.5 mm and less than 8 mm.

3. The drainage pump according to claim 1 or 2, characterized in that, The concave surface is formed from the inner periphery of the lower end face of the suction tube to the outer periphery. The radial width of the concave surface is the same as the wall thickness of the inhalation tube.

4. The drainage pump according to claim 1 or 2, characterized in that, The outer diameter of the inhalation tube is 16 mm or more and 25 mm or less.

5. The drainage pump according to claim 1, characterized in that, The concave surface faces downwards.

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