JP5275264B2 - Drainage pump - Google Patents

Description

  The present invention relates to a drainage pump suitable for draining, for example, water accumulated in a drain pan of an air conditioner.

  Conventionally, as drainage pumps for air conditioners, for example, those disclosed in Japanese Utility Model Publication No. 6-67887 (Patent Document 1), Japanese Patent No. 3524611 (Patent Document 2) and Japanese Patent No. 3511044 (Patent Document 3) There is. This type of drainage pump has, for example, a cross-shaped small blade (auxiliary blade) placed in a cylindrical suction port formed in the lower part of the pump chamber. By rotating this small blade, the water in the drain pan is sucked from the suction port. To do. In general, there are two main types of suction ports: straight or narrowing the bottom end a little (see Patent Document 1 or Patent Document 2). Such a shape is effective in both cases in order to prioritize the amount of drainage and minimize the water remaining in the drain pan.

Japanese Utility Model Publication No. 6-67887 Japanese Patent No. 3524611 Japanese Patent No. 3511044

  However, at the time of balance, that is, when the drain pump and the pipe ahead are filled with drain water without entering and leaving water, there is a possibility that air is sucked in the vicinity of the suction port. This tendency is particularly great in a drainage pump (drain pump) using a DC motor. This is because in the DC motor, the rotational speed increases as the load decreases. Moreover, the capacity of the drainage pump is determined by the amount of drainage at the high head, but when the head is low, the load decreases and the number of revolutions exceeds the required number of revolutions at the low head, and the amount of drainage increases to the discharge limit. It became a factor of noise vibration.

  Compared with the straightened suction port of the drainage pump and the one with the lower end slightly narrowed as in Patent Document 1 and Patent Document 2, the narrowed one has a larger amount of drainage and can suck in air during balancing. There is a tendency to increase sex. For example, as shown in FIG. 11, in the case where the narrow diameter portion is formed at the lower end of the suction port, the water in the drain pan is close to the lower end of the suction port, and air is sucked in the vicinity of the water surface at the lower end. . In particular, when a DC motor is used, the number of revolutions increases as the load decreases, so that it appears remarkably.

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to reduce noise by reducing air suction at the suction port of the drainage pump.

According to a first aspect of the present invention, there is provided a drainage pump including a pump body having a cylindrical suction port formed at a lower end portion and a discharge port formed at an upper side surface, an impeller rotatably disposed in the pump body, and the impeller The impeller includes a shaft portion connected to a drive shaft of the motor, and a plurality of plate-shaped small blades extending in parallel along the axial direction below the shaft portion; A centrifugal force acting portion for guiding fluid to the inner peripheral side of the pump main body between the shaft portion and the small blades, and rotating the small blades in the suction port, thereby allowing fluid to flow from the suction port. In the drainage pump that sucks and discharges fluid from the discharge port, the upper inner wall that hangs from the upper end of the suction port has a cylindrical shape parallel to the axial direction, and is substantially the center in the vertical direction of the entire inner wall of the suction port. part of the The lower end of the upper inner wall of the cylindrical depending from said top end there, characterized in that the narrow diameter portion having a reduced inner diameter than the inner diameter of the lower and upper ends of the intake lump port is formed.

  The drainage pump according to claim 2 is the drainage pump according to claim 1, wherein a distance from a lower end portion of the small blade to the narrow-diameter portion is 30 to a total length in the suction port of the small blade. The distance is 50%.

  According to the drainage pump of claim 1, by shifting the position of the narrow diameter portion in the suction port from the lower end to the motor side from the lower end of the small blade, that is, by narrowing the inner diameter in the middle of the cylindrical space of the suction port, Dividing the amount of small blades into two halves at the narrow-diameter part makes it possible to control the amount of drainage to an appropriate amount, and the water level of the drain pan rises when balanced, allowing air to be sucked in at the lower end. Loss and quietness is obtained. Also, slime can be prevented from adhering due to the back flow in the narrow diameter portion.

  According to the drainage pump of the second aspect, in addition to the effect of the first aspect, the silence can be effectively secured.

It is a partial longitudinal cross-sectional view of the drainage pump of 1st Embodiment of this invention. It is a principal part expanded sectional view of the drainage pump of 1st Embodiment of this invention. It is the top view, side view, and bottom view of the impeller of the drainage pump of 1st Embodiment of this invention. It is the external appearance side view and external appearance top view of the drainage pump of 1st Embodiment of this invention. It is a figure explaining the effect | action of the drainage pump of 1st Embodiment of this invention. It is a graph which shows the measurement result of the position and noise of a narrow diameter part in the drainage pump of 1st Embodiment of this invention. It is a figure which shows the suction inlet and narrow diameter part in the drainage pump of 2nd Embodiment of this invention. It is a figure which shows the suction inlet and narrow diameter part in the drainage pump of 3rd Embodiment of this invention. It is a figure which shows the suction inlet and narrow diameter part in the drainage pump of 4th Embodiment of this invention. It is a figure which shows the suction inlet and narrow diameter part in the drainage pump of 5th Embodiment of this invention. It is a figure explaining the effect | action and problem of the conventional drainage pump.

  Next, an embodiment of the drainage pump of the present invention will be described with reference to the drawings. FIG. 1 is a partial longitudinal sectional view of a drainage pump according to the first embodiment, FIG. 2 is an enlarged sectional view of an essential part of the drainage pump according to the first embodiment, and FIG. 3 is a plan view of an impeller of the drainage pump according to the first embodiment. FIG. 4 is an external side view and an external top view of the drainage pump according to the first embodiment. Note that the concept of “upper and lower” in the following description corresponds to the upper and lower sides in the drawing of FIG. The drainage pump of this embodiment has a pump main body 1, and the pump main body 1 includes a hollow cylindrical pump chamber 11, a cylindrical suction port 12 at the lower end, and a discharge port 13 at the side. A discharge pipe (not shown) is connected to the discharge port 13. An impeller 2 shown in FIG. 3 is disposed in the pump chamber 11. A motor case 31 of the motor 3 is fixed to the upper opening of the pump body 1. The motor case 31 has a wall 31a that hangs in the vicinity of the inner peripheral wall of the pump chamber 11, a draining portion 31b is formed at the center of the motor case 31, and an opening 31c is formed at the upper central portion of the draining portion 31b. Yes. The motor 3 of this embodiment is a three-phase DC brushless motor.

Further, the drive shaft 32 of the motor 3 protrudes downward and passes through the opening 31 c of the motor case 31. The impeller 2 is fixed to the drive shaft 32. As shown in FIG. 3, the impeller 2 includes a shaft portion 21 connected to the drive shaft 32 of the motor 3, and four plate-like small blades extending along the axis P direction below the shaft portion 21. 22. Further, a donut-shaped hollow conical plate 23 formed in a substantially inverted conical shape is provided between the shaft portion 21 and the small blades 22, and extends on the hollow conical plate 23 in the axis P direction. A large number of prismatic large-diameter blades 24 are provided.

  The small blades 22 of the impeller 2 are disposed in the suction port 12, and the lower end portion 221 of the small blades 22 is located slightly in the suction port 12 from the lower end portion 121 of the suction port 12. A narrow-diameter portion 12 a having an inner diameter smaller than the inner diameters of the lower end portion 121 and the upper end portion 122 of the suction port 12 is formed on the inner side of the suction port 12 at a part of the center of the inner wall in the vertical direction. . In this 1st Embodiment, it is a taper surface from the narrow diameter part 12a to the lower end part 121 of the suction inlet 12. FIG. As described above, the shape of the suction port 12 is such that the narrow-diameter portion 12a is located closer to the motor 3 than the lower end portion 221 of the small blade 22 and divides the pumping force of the small blade 22 into two.

  With the above configuration, the impeller 2 is rotated by driving the motor 3 and the small blades 22 are rotated in the suction port 12, so that the water in the drain pan rises into the suction port 12, and the water is hollow cone by centrifugal force. Move to the plate 23 side. Then, the water in the pump chamber 11 is rotated by the hollow conical plate 23 and the large-diameter blade 24, and water is discharged from the discharge port 13 by the centrifugal force. At this time, the large-diameter blades 24 are arranged such that the prismatic parts thereof face the same direction, and when the impeller 2 rotates, water is sprayed on one surface of the prismatic part, and by repeating the paint on one corner, Create a smooth water flow. The hollow conical plate 23 and the large diameter blade 24 correspond to a centrifugal force acting part.

  As shown in FIG. 5, the flow of water sucked from the suction port 12 becomes a normal flow toward the discharge port 13 by the water passing between the narrow diameter portion 12 a and the small blades 22. However, due to the narrow-diameter portion 12a, a part of the flow is directed toward the reverse direction (drain pan side), the amount of drainage is reduced, and the amount of drainage can be controlled to an appropriate amount. As a result, a certain level of water can be maintained in the drain pan when balanced, and noise can be reduced without inhaling air as in the prior art described with reference to FIG. In addition, this unique flow means that there is always a flow of water around the lower end 121 of the suction port 12 even at the time of balance, and generally a thick gel-like slime that floats and accumulates adheres. It becomes difficult to do. It is also possible to wind up and suck in the drain pan dust that has started to settle, and flow it out as it is. If the wings are simply shortened without forming the narrow-diameter part, it is not possible to prevent the slime from adhering to the reverse flow, and there is a possibility that a non-moving part of water will be formed in the suction port, which may block the suction port. This is not the case with the present invention.

  In this embodiment, the wall 14 that hangs on the outer periphery of the pump body 1 and the wall 31a that the motor case 31 suspends constitute a labyrinth structure. The bearing of No. 3 is protected, so that the web sound is not released outside. Further, attachment portions 3a, 3b, and 3c having an unequal pitch are formed at the upper end of the motor case 31, thereby obtaining an effect of preventing erroneous attachment.

  Next, the dimension of the principal part in 1st Embodiment is demonstrated. As shown in FIG. 2, the length L1 of the small blade 22 is 16 mm, and the length L2 from the lower end portion 221 of the small blade 22 to the narrow diameter portion 12a is 30% to 50% of L1. A length L3 from the lower end 121 of the suction port 12 to the lower end 221 of the small blade 22 is 1.5 mm. The opening diameter of the lower end portion 121 of the suction port 12 is φ12.5 mm, and the tapered surface is opened at an angle of 20 ° from the narrow diameter portion 12 a to the lower end portion 121 of the suction port 12. The width L4 of the small blade 22 is 8 mm, the inclination angle inside the narrow diameter portion 12a (on the pump chamber 11 side) is 45 °, and the gap L5 between the inner end of the narrow diameter portion 12a and the small blade 22 is , Which is a half of 25% of the width L4 of the small blade 22. Further, the thickness L6 of the small blade 22 is 2 mm. The thickness L6 is preferably 18% to 25% of the width L4.

  FIG. 5 is a graph showing a measurement result of the relationship between the position of the narrow diameter portion 12a and the noise when the position of the narrow diameter portion 12a is changed in the first embodiment. The vertical axis represents the noise value (decibel), and the horizontal axis represents the percentage (%) with respect to the total length L1 of the small blade 22 at the distance L2 from the end 221 of the small blade 22 to the narrow diameter portion 12a. Each graph corresponds to a case where the heads (the height at which the pump lifts water) are different, and shows cases where the heads are 150 mm, 300 mm, 500 mm, 800 mm, and 1200 mm. Among these, the normal range of the lift is 500 mm to 800 mm, and it can be seen that there is a silent effect when the position of the narrow diameter portion 12a is 30% to 50% in this normal range. In particular, the position of the narrow-diameter portion 12a is preferably 37% to 45%.

  In the first embodiment, the shape from the narrow-diameter portion 12a to the lower end portion 121 of the suction port 12 is a tapered surface, but it may be as in the second to fifth embodiments shown in FIGS. In these second to fifth embodiments, the structure other than the narrow-diameter portion of the suction port 12 is the same as that of the first embodiment.

  In the second embodiment shown in FIG. 7, the narrow-diameter portion 12b of the suction port 12 has an inner (pump chamber 11 side) and outer inclination angle of 45 ° and a center-side tip angle of 90 °. That is, the inside and outside of the narrow diameter portion 12b have the same inner diameter (a diameter larger than the narrow diameter portion). In the third embodiment shown in FIG. 8, the narrow-diameter portion 12 c of the suction port 12 has a shape protruding in a circular arc shape in the center side. Also in this case, the inside and outside of the diameter portion 12c have the same inner diameter (a diameter larger than the narrow diameter portion). In 4th Embodiment shown in FIG. 9, the narrow diameter part 12d of the suction inlet 12 curves the base part, and the flow of water becomes smooth. The narrow-diameter portion 12e of the suction port 12 of the fifth embodiment shown in FIG. 10 has an inclination angle of 45 ° on the inner side (the pump chamber 11 side) and the outer side, and is outside the inner diameter A inside the narrow-diameter portion 12e. The inner diameter B is made larger.

  In each of these embodiments, the same silent effect as that of the first embodiment can be obtained by making the positions of the narrow diameter portions 12b to 12e the same as those of the first embodiment. Also, slime is difficult to adhere.

  In the above embodiment, the centrifugal force acting portion has a structure in which the prismatic large-diameter blades 24 are provided on the hollow conical plate 23. For example, as in Patent Document 3, a plate-like shape is provided on the hollow conical plate. A structure provided with a plurality of blades may also be used.

DESCRIPTION OF SYMBOLS 1 Pump main body 2 Impeller 11 Pump chamber 12 Suction port 12a-12e Narrow diameter part 13 Discharge port 22 Small blade | wing 221 Lower end part 3 Motor 31 Drive shaft

Claims (2)

A pump body having a cylindrical suction port formed at the lower end and a discharge port formed on the upper side surface, an impeller disposed rotatably in the pump body, and a motor for rotating the impeller, The impeller includes a shaft portion connected to a drive shaft of the motor, a plurality of plate-like small blades extending in parallel along the axial direction below the shaft portion, the shaft portion and the small blades. A centrifugal force acting portion that guides the fluid to the inner peripheral side of the pump body, and by rotating the small blade in the suction port, the fluid is sucked from the suction port, and the fluid is sucked from the discharge port. In the drainage pump designed to discharge,
The upper inner wall that hangs down from the upper end of the suction port has a cylindrical shape parallel to the axial direction, and is a part of the substantially upper center of the vertical direction of the entire inner wall of the suction port and hangs down from the upper end. A drainage pump characterized in that a narrow-diameter portion whose inner diameter is smaller than the inner diameter of the lower end and the upper end of the suction port is formed at the lower end.   The distance from the lower end part of the said small blade to the said narrow diameter part is a distance of 30%-50% with respect to the full length in the said suction inlet of the said small blade. Drainage pump.

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