Drain pump

Abstract

The drainage pump has: an electric motor and a pump main body, the pump main body including a housing, a rotary vane, and a cover. The upper part of the housing is open, a suction port is provided at the lower end of the housing, and a discharge port is provided at the side of the housing. The rotary vane is connected to the electric motor. The cover has a through-hole at the center and is installed at the upper end of the housing. A pump chamber is defined by the housing and the cover. The discharge port has a discharge port inlet that opens on the inner peripheral surface of the pump chamber across the joint portion between the inner peripheral surface formed by the housing and the inner peripheral surface formed by the cover. The corner portion at the boundary between the inner peripheral surface of the housing and the inner surface of the discharge port in the discharge port inlet is chamfered.

Description

Technical Field

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

[0002] As disclosed in Japanese Unexamined Patent Application Publication No. 2016-113941, conventionally, in an air conditioner in the form of being embedded in the ceiling of a room, there is a drainage pan that receives the drainage condensed on the surface of the indoor heat exchanger of the air conditioner. A drainage pump (discharge pump) is used to discharge the drainage in the drainage pan to the outside.

[0003] The drainage pump is composed of a motor and a pump main body. The pump main body includes a housing, a rotating blade, and a cover. The upper part of the housing is open, and a suction port is provided at the lower end of the housing and a discharge port is provided at the side part formed by a substantially cylindrical inner peripheral wall. The rotating blade is connected to the housing, and the cover has a through hole in the central part and is mounted on the upper end of the housing. In addition, a pump chamber is defined by the housing and the cover. The discharge port has a discharge port inlet that opens into the pump chamber.

[0004] Technical Problem to be Solved by the Invention

[0005] However, in the above conventional example, due to the demolding structure of the mold for forming the housing, a corner portion with an acute angle, a right angle, or an obtuse angle is formed at the portion where the discharge port inlet opens into the pump chamber (outer corner portion). Therefore, it is considered that when the drainage pump operates and the drainage flows from the pump chamber into the discharge port inlet and is discharged, a loss occurs at this boundary portion. Summary of the Invention

[0006] An object of the present invention is to provide a drainage pump that can improve drainage efficiency.

[0007] Technical Means for Solving the Technical Problem

[0008] To solve the above technical problem, the drainage pump of the present invention has: a motor and a pump main body. The pump main body includes a housing, a rotating blade, and a cover. The upper part of the housing is open, and a suction port is provided at the lower end of the housing and a discharge port is provided at the side part of the housing. The rotating blade is connected to the motor. The cover has a through hole in the central part and is mounted on the upper end of the housing. A pump chamber is defined by the housing and the cover. The discharge port has a discharge port inlet that opens into the pump chamber. The pump chamber has a substantially cylindrical inner peripheral surface formed by the engagement of the housing and the cover. The discharge port inlet opens at the joint portion of the housing and the cover in the inner peripheral surface of the pump chamber. The corner portion located at the boundary between the inner peripheral surface formed by the housing and the inner surface of the discharge port in the inner peripheral surface of the pump chamber is chamfered.

[0009] In this drainage pump, alternatively, a stepped portion that extends radially outward from the upper edge position of the inner circumferential surface of the housing and has a width in the radial direction of the housing is formed at the joint portion of the housing. The inlet of the discharge port opens above the stepped portion with respect to the housing, and the chamfer width of the corner portion is set to be equal to or less than the width of the stepped portion. Further, alternatively, the corner portion located at the boundary between the inner circumferential surface formed by the cover and the inner surface of the discharge port is chamfered. Further, alternatively, in the corner portion, the chamfer width of the portion located on the upstream side of the drainage flow from the pump chamber to the inlet of the discharge port is larger than the chamfer width of the portion located on the downstream side.

[0010] Advantages of the Invention

[0011] According to the present invention, a drainage pump capable of improving drainage efficiency can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a longitudinal sectional view showing a drainage pump according to an embodiment of the present invention.

[0013] Figure 2 is a perspective view showing the housing.

[0014] Figure 3 is an enlarged perspective view showing the housing side portion of the inlet of the discharge port.

[0015] Figure 4 is a sectional view showing the housing and the cover cut along a plane passing through the center line of the discharge port.

[0016] Figure 5 (A) of is a magnified sectional view showing Figure 4 part A in. (B) is a magnified sectional view showing a modified example of (A) of Figure 5 .

[0017] Figure 6 is a top view showing the housing.

[0018] Figure 7 is showing Figure 6 the magnified top view of part B in.

[0019] Figure 8 is a top view corresponding to Figure 7 a modified example 1 of the housing side portion of the inlet of the discharge port.

[0020] Figure 9 is a top view corresponding to Figure 7 a modified example 2 of the housing side portion of the inlet of the discharge port.

[0021] Figure 10This is a perspective view corresponding to Modification Example 3 of the housing-side portion representing the outlet inlet. Figure 3

[0022] Figure 11 This is a perspective view corresponding to Modification Example 4 of the housing-side portion representing the outlet inlet. Figure 3 Detailed Implementation Manner

[0023] Hereinafter, the manner for implementing the present invention will be described based on the accompanying drawings. In Figure 1 this example, the drainage pump 10 of the present embodiment includes a motor 12 and a pump main body 20. The motor 12 is disposed above the pump main body 20. A motor case 30 for supporting the motor 12 is provided between the motor 12 and the pump main body 20. The pump main body 20 is made of, for example, synthetic resin, and includes a housing 40, a rotary vane 50, and a cover 32, and a pump chamber 44 having a substantially cylindrical inner peripheral surface 44A is formed by joining the housing 40 and the cover 32.

[0024] The upper part of the housing 40 is open, and a suction port 42 is provided at the lower end portion of the housing 40 and a discharge port 46 is provided at the side portion of the housing 40. The suction port 42 is formed in a tubular shape having an opening 43 at the lower end portion. The discharge port 46 includes a discharge port inlet 48 that opens into the pump chamber 44 and protrudes laterally. The discharge port 46 is disposed radially outside the rotation axis 50CL of the rotary vane 50 described later. The axis 46CL of the discharge port 46 is disposed in the horizontal direction. In addition, a shaft portion 52 located at the center of the rotary vane 50 described later is positioned on the axis 46CL of the discharge port 46.

[0025] When the drainage pump 10 is in use, a drainage pipe (not shown) for discharging the drainage discharged from the discharge port 46 to the outside of the pump main body 20 to an external drainage device or the like is installed at the discharge port 46. As Figure 2 shown, for example, a pair of claw portions 24 for fixing the motor case 30 are provided on the housing 40. In addition, the discharge port 46 is not limited to a structure integrally formed with the housing 40, and may also be a structure separately formed from the housing 40 and assembled to the housing 40.

[0026] As Figure 1 ​​As shown, the rotating blade 50 is connected to the motor 12 and is housed 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 large-diameter blades 60 extending radially outward from the outer peripheral portion of the shaft portion 52 in the radial direction of the rotating shaft 50CL (in other words, radially outward); and a plurality of flat small-diameter blades 61 connected to the lower end edge portions of the large-diameter blades 60 and inserted into the suction port 42. The large-diameter blades 60 are provided at equal angles in the circumferential direction, for example. The lower end edge portions of the large-diameter blades 60 are formed in a conical shape that slopes downward on the inner diameter side. Each of these lower end edge portions is connected to a disk-shaped annular member 62 having a plurality of fan-shaped openings 58 at the center.

[0027] The large-diameter blades 60 of the rotating blade 50 are provided on the shaft portion 52 in such a manner that they are positioned on the front surface of the discharge port 46, that is, 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.

[0028] The shaft portion 52 passes through the through-hole 36 and protrudes toward the motor 12 side. The through-hole 36 serves as an air hole formed in the center of the cover 32. The drive shaft of the motor 12 is inserted into and fixed to a hole provided along the central axis of the shaft portion 52. In addition, a gap is provided between the through-hole 36 and the shaft portion 52.

[0029] A water control disk 14 is mounted on the upper surface of the shaft portion 52. The water control disk 14 has the function of preventing the drained water from directly scattering toward the motor 12 even if the drained water is blown out from the through-hole 36 of the cover 32.

[0030] The motor housing 30 includes a cylindrical portion 22 that can be divided vertically, and the motor 12 is housed in the upper part of the cylindrical portion 22. In addition, a longitudinally long slit-shaped drain hole (in other words, an opening for drainage), not shown, is formed in the side portion of the cylindrical portion 22.

[0031] As Figure 1 shown, the cover 32 has a through-hole 36 at the central portion and is mounted on the upper end portion of the housing 40. Specifically, the cover 32 is formed integrally with the lower end of the cylindrical portion 22 of the motor housing 30, for example. In addition, the cover 32 is fitted into the housing 40 in a state where a sealing member 34 is clamped between the cover 32 and the upper stepped portion 19 of the housing 40. The cover 32 is fixed to the housing 40 by fitting the claw portions 24 ( Figure 2 ) into the motor housing 30. In the pump main body 20, the pump chamber 44 is defined by the housing 40 and the cover 32.

[0032] A drain pan (not shown) for temporarily storing the drained water discharged from an air conditioning device or the like is disposed below the suction port 42.

[0033] As Figure 3As shown, a stepped portion 18 is formed at a portion of the housing 40 that engages with the cover 32. The stepped portion 18 extends radially outward from the upper edge position of the inner peripheral surface 40A of the housing 40 and has a width W ( Figure 7 ) in the radial direction of the housing 40. As Figure 5 shown, when the cover 32 is mounted on the housing 40 (i.e., when the housing 40 engages with the cover 32), the lower end 32B of the cover 32 abuts or is close to the stepped portion 18. The inner peripheral surface 44A of the pump chamber 44 is constituted by the inner peripheral surface 40A of the housing 40 and the inner peripheral surface 32A of the cover 32. Above the housing 40 side portion that forms a part of the discharge port inlet 48, an opening is formed in the stepped portion 18 with respect to the housing 40. Thus, when the housing 40 is viewed from above, the stepped portion 18 is not a complete circular ring shape, but is formed as an arc shape or a C shape that is discontinuous at the portion of the discharge port inlet 48. In a state where the housing 40 and the cover 32 are engaged, the discharge port inlet 48 is positioned so as to open in the inner peripheral surface 44A of the pump chamber 44 across the engagement portion between the inner peripheral surface 40A formed by the housing 40 and the inner peripheral surface 32A formed by the cover 32.

[0034] In addition, the housing 40 side portion that forms a part of the discharge port inlet 48 is formed in a substantially U shape. In other words, in a portion of the discharge port 46 close to the discharge port inlet 48, the inner surface 56 is formed in a U-shaped cross section. Specifically, the inner surface 56 is constituted by a pair of planar side surfaces 56A and a bottom surface 56B, such as an arc shape, that connects the lower ends of the side surfaces 56A to each other. The side surfaces 56A are formed parallel to the axial direction of the suction port 42. This is because when molding the inner surface 56 of the portion of the discharge port inlet 48, the upper mold (not shown) is pulled out upward in the axial direction of the suction port 42. The axis of the suction port 42 corresponds to the rotation axis 50CL ( Figure 1 ) of a rotating blade 50 described later. The discharge port 46 may also change to a circular cross section on the downstream side of the discharge port inlet 48. In addition, the cross-sectional area of the downstream side of the discharge port 46 may also be larger than the cross-sectional area of the discharge port inlet 48.

[0035] As Figures 2 to 6 shown, the corner portion 16 of the housing 40 side portion of the discharge port inlet 48 is chamfered. The corner portion 16 is a portion located at the boundary between the inner peripheral surface 40A of the housing 40 in the discharge port inlet 48 and the inner surface 56 of the discharge port 46. The chamfering of the corner portion 16 is a so-called R surface that is, for example, a circular arc shape in cross section. In addition, in this specification, "chamfering" includes not only cases where chamfering processes such as cutting and plastic working are performed on the outer corner portion having an angle to form an R surface or a C surface at the outer corner portion, but also cases where an outer corner portion having a shape of an R surface or a C surface is formed from a plastic material by casting, injection molding, etc. For the sake of convenience in explanation, in the latter case where chamfering processing is not actually performed, expressions such as "structure after chamfering the corner portion" and "chamfering of the corner portion" are also used.

[0036] In Figure 5 the example shown in (A), although the corners at the lower end of the cover 32 that form the cover 32 side portion of the discharge port inlet 48 are not chamfered, in order to further improve the drainage efficiency, it is also possible, as shown in (B) of Figure 5 , to chamfer the corner portion 54 in the same manner as the corner portion 16 of the housing 40 side portion of the discharge port inlet 48. As a result, the corner portion 54 located at the boundary between the inner peripheral surface 32A formed by the cover 32 and the inner surface 56 of the discharge port 46 is also chamfered. In addition, although not shown in the drawings, by providing a protrusion on a part of the cover 32 that enters the upper part of the housing 40 side portion of the discharge port inlet 48 from the step portion 18, and providing an arc-shaped ceiling surface that is line-symmetric with the bottom surface 56B of the discharge port 46 on the protrusion, the shape of the discharge port inlet 48 can also be made circular. Further, the corners of the protrusion can also be chamfered. In this way, the corner portions 16 and 54 are formed across the housing 40 and the cover 32, and thus there is a structure in which at least a part of the corner portions 16 and 54 is chamfered.

[0037] As shown in Figure 6 , Figure 7 , the chamfer width (radius of curvature) R of the corner portion 16 is set to be equal to or less than the width W of the step portion 18. The minimum value of the chamfer width R is, for example, 0.2 mm. Although in the illustrated example the chamfer width R is smaller than the width W, the chamfer width R can also be the same as the width W. In addition, the chamfer width R of the corner portion 16 of the housing 40 when viewed from above is equally set on both sides of the discharge port inlet 48.

[0038] In addition, in order to further improve the drainage efficiency, as in the modification 1 shown in Figure 8 , it is also possible that in the corner portion 16, the chamfer width R1 of the portion located on the upstream side of the drainage water flow F from the pump chamber 44 to the discharge port inlet 48 is larger than the chamfer width R2 of the portion located on the downstream side. In this case, since the chamfer width R1 of the portion located on the upstream side of the drainage water flow F is larger, the drainage can easily flow smoothly into the discharge port inlet 48. In addition, since the chamfer width R2 of the portion located on the downstream side of the drainage water flow F is smaller, it is possible to prevent the drainage from passing through the discharge port inlet 48 excessively and circulating again in the pump chamber 44. In addition, as in the modification 2 shown in Figure 9 , the chamfer of the corner portion 16 may not be limited to the R surface with a circular cross-section, but may be a so-called C surface with a flat cross-section.

[0039] Furthermore, the housing 40 side portion of the discharge port inlet 48 is not limited to a substantially U shape, as shown in Figure 10As in the third modification example shown, it may also be a substantially quadrilateral shape. In this case, the circular cross-section discharge port 46 has a structure in which the discharge port inlet 48 opens in a substantially quadrilateral shape. In addition, the corner portions 16 of the three sides on the housing 40 side of the four sides of the discharge port inlet 48, excluding the side on the extension line of the step portion 18, are chamfered. In a structure in which the upper mold (not shown) is pulled out above the axis of the suction port 42 (in other words, the direction of the rotation axis 50CL of the rotating blade 50 described later), the housing 40 side portion of the discharge port inlet 48 having such a shape can be formed. In addition, instead of Figure 10 the third modification example, it may also be as in Figure 11 the fourth modification example shown, in which the discharge port 46 has a circular cross-section shape and the lower half circle portion of the discharge port inlet 48 is chamfered. Thereby, the continuity between the discharge port 46 and the discharge port inlet 48 is increased, and the discharge of drainage can be further effectively performed.

[0040] (Function)

[0041] The present embodiment is configured as described above, and its function will be described below. In Figure 1 the drainage pump 10 of the present embodiment, the lower end of the suction port 42 is appropriately provided so as to be located below the surface of the drainage stored in the drainage pan (not shown). Then, when the drive motor 12 is driven to rotate the rotating blade 50 at high speed, the drainage stored in the drainage pan is sucked up from the suction port 42 and discharged from the discharge port 46 via the pump chamber 44. The drainage discharged from the discharge port 46 is discharged to an external drainage device or the like via a drainage pipe (not shown). The water flow containing bubbles generated from the drainage by the rotation of the rotating blade 50 obtains a centrifugal force in the pump chamber 44 and smoothly flows toward the discharge port 46, and is discharged to the outside via the drainage pipe.

[0042] In the present embodiment, as Figure 7 shown, since the corner portion 16 at the boundary between the inner peripheral surface 40A of the housing 40 where the housing 40 side portion of the discharge port inlet 48 opens and the inner surface 56 of the discharge port 46 is chamfered, the flow of the drainage is less likely to be disturbed compared to the case where the corner portion 16 is not chamfered, so that the drainage smoothly flows from the pump chamber 44 into the discharge port inlet 48. Therefore, the drainage efficiency of the drainage pump 10 can be improved.

[0043] In Figure 8In the first modification example shown, since the chamfer width R1 of the portion on the upstream side of the water flow F for drainage in the pump chamber 44 (i.e., the rear side in the rotation direction of the rotary vane 50) is larger than the chamfer width R2 of the portion on the downstream side (i.e., the front side in the rotation direction of the rotary vane 50), the drainage can easily flow smoothly into the discharge port inlet 48. In addition, since the chamfer width R2 of the portion on the downstream side of the water flow F for drainage is smaller than the chamfer width R1 of the portion on the upstream side, the drainage is easily caught by the corner portion 16 on the downstream side. Therefore, the loss of the drainage being repeatedly circulated in the pump chamber 44 through the discharge port inlet 48 is reduced.

[0044] In Figure 9 In the second modification example shown, although the chamfer of the corner portion 16 is the C surface, even with such a C surface, the drainage can flow smoothly from the pump chamber 44 into the discharge port inlet 48 compared to the case where there is no chamfer at the corner portion 16. In addition, in Figure 10 In the third modification example shown, the discharge port 46 is formed in a sectional circular shape. On the other hand, the portion of the discharge port inlet 48 on the housing 40 side is formed in a substantially U shape and the corner portion 16 of the discharge port inlet 48 is chamfered. Therefore, even if the discharge port 46 is in a sectional circular shape, the discharge of the drainage can be effectively performed through the discharge port inlet 48 whose corner portion 16 is chamfered.

[0045] In addition, in Figure 11 In the fourth modification example shown, the discharge port 46 is formed in a sectional circular shape, and the lower semicircular portion of the discharge port inlet 48 is chamfered. Since the continuity of the shapes of the discharge port 46 and the discharge port inlet 48 is increased, the discharge of the drainage can be further effectively performed.

[0046] [Other Embodiments]

[0047] As described above, an example of the embodiment of the present invention has been described. However, the embodiment of the present invention is not limited to the above, and it goes without saying that various modifications can be made within the scope not departing from the gist of the present invention in addition to the above.

[0048] In the above embodiment, although a stepped portion 18 that extends radially outward from the position of the inner peripheral surface 40A of the housing 40 and has a width in the radial direction is formed at the upper edge of the inner peripheral surface 40A of the housing 40, and the upper part of the discharge port inlet 48 opens at the stepped portion 18, the portion where the upper part of the discharge port inlet 48 opens is not limited to such a stepped portion 18. Considering the mold release property, if a chamfer can be formed at the corner portion 16 of the discharge port inlet 48, the upper part of the discharge port inlet 48 can also open at other portions.

[0049] In addition, the range in which the chamfer is formed in the corner portion 16 is not limited to the whole of the corner portion 16. The chamfer can also be formed in a part of the corner portion 16.

[0050] The entirety of the invention of Japanese Patent Application No. 2020-47039, filed on March 17, 2020, is incorporated herein by reference as a reference group.

[0051] All documents, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as each document, patent application, and technical standard is specifically and individually indicated to be incorporated by reference.

Claims

1. A drainage pump having: an electric motor and a pump main body, the pump main body including a housing, a rotary vane, and a cover, the upper part of the housing being open, a suction port being provided at the lower end of the housing and a discharge port being provided at the side of the housing, the rotary vane being connected to the electric motor, the cover having a through-hole in the central part and being mounted on the upper end of the housing, a pump chamber being defined by the housing and the cover, and the discharge port having a discharge port inlet opening into the pump chamber, wherein, the pump chamber has a substantially cylindrical inner peripheral surface formed by the engagement of the housing and the cover, the discharge port inlet opens into the inner peripheral surface of the pump chamber across the inner peripheral surface formed by the housing and the inner peripheral surface formed by the cover, the corner portion at the boundary between the inner peripheral surface of the housing and the inner surface of the discharge port in the discharge port inlet is chamfered, a stepped portion is formed at the portion of the housing that engages with the cover, the stepped portion extending radially outward from the upper edge position of the inner peripheral surface and having a width in the radial direction of the housing, the upper part of the housing side portion that forms a part of the discharge port inlet opens into the stepped portion with respect to the housing, the chamfer width of the corner portion is set to be equal to or less than the width of the stepped portion.

2. The drainage pump according to claim 1, wherein, the corner portion at the boundary between the inner peripheral surface of the cover and the inner surface of the discharge port in the discharge port inlet is chamfered.

3. The drainage pump according to claim 1 or 2, wherein, in the corner portion, the chamfer width of the portion located on the upstream side of the flow of drainage from the pump chamber to the discharge port inlet is larger than the chamfer width of the portion located on the downstream side.

Images