JP2006090279A - Impeller for liquid pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impeller 30 for a liquid pump forming a recessed part 35 on a rear face, fixing a plate-like lid member 40 covering the recessed part 35 to a seat part 36 around the recessed part 35 and capable of discharging an intrusion object in the recessed part 35 by a simple configuration to keep mass balance and prevent vibration. <P>SOLUTION: A discharge port 43 for discharging the intrusion object in the recessed part 35 is provided in the lid member 40. This discharge port 43 is constituted by, for example, a cut-out part 42 provided at an outer peripheral fringe of the lid member 40. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an impeller for a liquid pump provided in a liquid pump used for pumping up liquid such as sewage in a sewage tank, a manhole pump station, a reservoir, and the like.

  Conventionally, an impeller for a liquid pump has been known in which an annular recess is provided on the back surface of the shroud to reduce the weight of the impeller and to maintain a mass balance. This impeller for a liquid pump is designed to maintain a mass balance in a state where there is no intruder in the recess (that is, the density of air inside the recess is the same as the density of air outside the recess). . For this reason, when intruders accumulate in the recesses, the mass balance is lost, and problems such as vibrations occur.

Therefore, for example, in Patent Document 1, a seat is provided on the outer periphery of the annular recess on the back surface of the shroud, and a masking plate (lid member) is fastened and fixed to the seat by a bolt to prevent intruders.
JP 2004-218574 A

  However, in the conventional liquid pump impeller, if the liquid pump impeller is used in the liquid, the lid member is simply fastened with the bolt to cover the concave portion, so that the liquid can be completely prevented from entering the concave portion. Cannot be prevented. For this reason, there existed a problem that mass balance collapse | crumbled by the liquid which penetrate | invaded.

  Furthermore, when a liquid pump impeller is manufactured in a factory and then a performance test is performed, if liquid accumulates in the recess, the liquid leaks during packaging or transportation.

  On the other hand, in order to prevent the intrusion of liquid into the recess, the sealing performance can be improved not only by bolting the lid member but also by another sealing structure. However, in such a case, the structure becomes complicated and the cost is reduced. There is a problem above.

  The present invention has been made in view of such points, and the object of the present invention is to devise the structure of the lid member to discharge the intruder in the recess with a simple structure and maintain the mass balance. This is to prevent vibration of the impeller for the liquid pump.

  In order to achieve the above object, according to the present invention, the lid member is provided with a discharge port that allows the inside of the recess to communicate with the outside of the recess.

  Specifically, in the first invention, a liquid pump impeller in which a concave portion is formed on the back surface and a plate-like lid member covering the concave portion is fixed to a seat portion around the concave portion is an object. A discharge port is provided for discharging intruders in the recess.

  According to said structure, a big intrusion does not penetrate | invade into a recessed part by the cover member which covers a recessed part. When the impeller for the liquid pump is used in the liquid, the liquid enters the recess from the outlet of the lid member and fills the liquid, but the density of the liquid in the recess is the same as the density of the liquid outside the recess. Therefore, the mass balance is maintained. On the other hand, when the liquid pump impeller is exposed to the air due to a drop in the liquid level or the like, the liquid in the recess is discharged from the discharge port by the centrifugal force applied to the liquid pump impeller, and becomes a cavity. Since the density of air inside the recess and the density of air outside the recess are the same, the mass balance is maintained. In addition, if the liquid that has entered the recess in advance is drained from the discharge port by idling or tilting the impeller for the liquid pump, the liquid leaks from the recess at the time of shipment or transportation. This problem does not occur.

  In the second invention, the discharge port is formed by a notch or a hole provided on the outer peripheral edge of the lid member and a seat portion viewed from the notch or the hole.

  According to the above configuration, the discharge port for discharging the intruder in the recess is formed only by cutting out the outer peripheral edge of the lid member, and the opening surrounded by the notch or the hole and the notch or the seat portion viewed from the hole. It is formed. When the impeller for the liquid pump rotates, the intruder in the recess moves to the lid member side along the outer peripheral side wall of the recess by the centrifugal force, and is discharged to the outside from the discharge port.

  In the third invention, the discharge port is formed by providing a plurality of sets of slit portions opposed to the lid member, and pressing between the opposed slit portions against the back side or the front side to project.

  According to said structure, the discharge port for discharging | emitting the intrusion in a recessed part is provided by pressing between the opposing slit parts provided in the cover member against the back side or the front side, and making it protrude. Since the gap between the slits protrudes to the back side or the front side, the protruding part exerts a so-called back spring action to improve the pressure on the back side of the liquid pump impeller, and the shaft applied to the liquid pump impeller Directional thrust is reduced.

  In the fourth invention, a spiral passage is formed inside.

  According to the above configuration, the liquid pump impeller having a spiral passage inside generally has a large height in the axial direction, and thus it is necessary to provide a large concave portion in order to reduce the weight. For this reason, since the volume of a recessed part increases, the discharge | emission action of an intrusion is performed more effectively.

  As described above, according to the first aspect of the present invention, the discharge port is provided in the lid member that covers the recess provided on the back surface of the impeller for the liquid pump, and the intruder in the recess is discharged. For this reason, the mass balance can be maintained regardless of whether the liquid pump impeller is in the liquid or in the air, and the occurrence of vibration is prevented, so that the occurrence of noise and failure can be prevented. Further, since the liquid does not accumulate in the recess, it is possible to prevent the liquid from leaking out from the recess during shipment or transportation.

  According to the said 2nd invention, the outer peripheral edge of the cover member is notched and the discharge port is provided. For this reason, the intruder in the recess can be discharged with a simple structure to prevent noise and failure.

  According to the said 3rd invention, between each opposing slit part provided in the cover member is pressed against the back side or the front side, the discharge port is formed. For this reason, intruders in the recess can be discharged from the discharge port with a simple configuration to prevent noise and failure, and the axial thrust applied to the impeller for the liquid pump can be reduced by the back spring action. Therefore, the occurrence of a failure can be effectively prevented.

  In the fourth aspect of the invention, the spiral passage is formed inside. For this reason, since it is necessary to provide a big recessed part for weight reduction, the discharge | emission function of an intrusion can be performed still more effectively.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the following embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or a use.

(Embodiment 1)
FIG. 1 shows a submersible pump 1 provided with a liquid pump impeller 30 according to Embodiment 1 of the present invention. The submersible pump 1 includes a pump casing 10 in which an impeller 30 is disposed, and a motor 20 that is disposed above the pump casing 10 and rotates the impeller 30.

  The motor 20 surrounds the cylindrical stator casing 21 having a vertical shaft center, a rotating shaft 23 inserted through the shaft center portion of the stator casing 21, a rotor 22 attached to the rotating shaft 23, and the rotor 22. Thus, the stator 24 is attached to the inner peripheral surface of the stator casing 21.

  An oil casing 25 that covers the lower end surface of the stator casing 21 is provided at the lower end portion of the stator casing 21. The rotating shaft 23 passes through the axial center portion of the oil casing 25. The rotating shaft 23 is rotatably supported by a bearing 26 attached to the oil casing 25. The lower end surface of the oil casing 25 has an open shape, and the lower end surface is closed by the upper surface of the pump casing 10 provided with a through hole in the center. The rotary shaft 23 penetrates through a through hole provided in the center of the pump casing 10 and enters the pump casing 10. The rotating shaft 23 inserted through the oil casing 25 is sealed with a mechanical seal 27, and the oil casing 25 is filled with oil. A lower end portion of the rotary shaft 23 is located at an upper portion in the pump casing 10, and the impeller 30 is attached to the lower end portion.

  A suction port 15 is formed on the bottom surface of the pump casing 10 so as to face the rotary shaft 23. A discharge pipe portion 14 communicates with the inside of the pump casing 10. The discharge pipe portion 14 extends in a tangential direction with respect to the pump casing 10, and a discharge port 14 a for sewage or the like flowing out from the pump casing 10 is formed at the tip thereof. The discharge pipe portion 14 is slightly curved so that the discharge port 14a faces outward.

  The impeller 30 disposed in the pump casing 10 is rotated in a predetermined direction by the motor 20, and is rotated from the suction port 15 provided on the bottom surface of the pump casing 10 by the rotation of the impeller 30. Sewage is sucked into the pump casing 10. The sewage sucked into the pump casing 10 by the rotation of the impeller 30 is discharged from the discharge port 14a through the discharge pipe portion 14 by centrifugal force.

  As shown in FIGS. 2 and 3, the impeller 30 is formed in a substantially cylindrical shape, and a suction port 31 is provided on the front side (lower side) thereof. Inside the impeller 30, a hollow spiral passage 32 extending in a spiral manner is formed while gradually rising from the suction port 31 to the back side (upper side). The outer end of the spiral passage 32 reaches the outer periphery of the impeller 30, thereby forming a discharge port 33 on the side.

  As shown also in FIG. 3, a boss portion 34 for connecting the rotating shaft 23 protrudes from the shaft center on the back side (shroud side) of the impeller 30. A through hole 34 a reaching the spiral passage 32 is formed in the boss portion 34. The through hole 34a is provided with a key groove 34b. And the impeller 30 whole is attached to the lower end part of the rotating shaft 23 in the state stopped by the volt | bolt 12 inserted in the lower end part of the boss | hub part 34. FIG.

  Further, the impeller 30 is formed with a weight reducing recess 35 in a region where the spiral passage 32 is not provided so as to correspond to the spiral passage 32. On the outer periphery of the boss portion 34, an annular flat seat portion 36 is formed which is slightly cut from the periphery in a slightly wider range than the outer periphery of the recess 35. In the periphery of the seat portion 36, an uncut portion is left, and a step portion 37 is formed on the outer periphery of the seat portion 36. In the seat portion 36, three screw support portions 38 are provided at intervals of 120 ° so as to protrude into the recess 35. A screw hole 39 is formed in the screw support portion 38.

  A plate-like lid member 40 that covers the recess 35 is fixed to the seat portion 36 with three screws 41. The lid member 40 is made of, for example, a thin stainless steel plate having a thickness of about 1.6 mm, and rectangular cutouts 42 are provided at three locations on the outer peripheral edge thereof with an interval of 120 °, for example. The inner end portion of the notch 42 extends inward from the inner end portion 36 a of the seat portion 36.

  Therefore, the impeller 30 is in a state where the inner end portion 36a of the seat portion 36 can be viewed from the notch 42 of the lid member 40 when viewed from above. In this manner, the discharge port 43 is formed by the opening surrounded by the notch 42 and the inner end 36a of the seat 36 viewed from the notch 42. Through the discharge port 43, the inside and the outside of the recess 35 communicate with each other, and the intruder in the recess 35 can be discharged.

-Driving action-
Next, the operation of the submersible pump 1 provided with the liquid pump impeller 30 of the present embodiment will be described. The submersible pump 1 is used by being installed in a sewage tank, for example.

  First, outside the sewage tank, foreign matter does not enter the recess 35 of the impeller 30, and only air exists. In this state, since the density of the air inside the recess 35 and the density of the air outside the recess 35 are the same, the mass balance of the impeller 30 is maintained.

  Next, when the pump casing 10 is immersed in the sewage in the sewage tank, the motor 20 is driven and the rotating shaft 23 of the motor 20 is rotated. As a result, the impeller 30 disposed in the pump casing 10 is rotated, and sewage is sucked into the pump casing 10 from the suction port 15 provided on the bottom surface of the pump casing 10.

  The sewage sucked into the pump casing 10 flows through the spiral passage 32 by centrifugal force due to the rotation of the impeller 30, flows from the pump casing 10 into the discharge pipe portion 14, and is discharged from the discharge pipe portion 14. It is discharged from the outlet 14a.

  At this time, the inside of the recessed part 35 is filled with dirty water by the dirty water entering and exiting from the outlet 43 of the lid member 40 into the recessed part 35 of the impeller 30. However, since the size of the discharge port 43 is limited, a large intruder does not enter. In this state, the density of the sewage inside the recess 35 and the density of the sewage outside the recess 35 are substantially the same, so the mass balance is maintained.

  And when the water level falls and the submersible pump 1 appears from the surface of the water due to the action of the submersible pump 1 by sucking the sewage in the sewage tank, the lid member 40 is exposed to the air, and the sewage in the recess 35 is Then, it is discharged out of the recess 35 by centrifugal force from the discharge port 43. By continuously rotating the submersible pump 1 for several seconds, all invaders in the recess 35 are discharged through the discharge port 43.

-Effect of Embodiment 1-
Therefore, according to the impeller 30 for a liquid pump according to the first embodiment of the present invention, the discharge port 43 is provided in the lid member 40 that covers the recess 35 provided on the back surface of the impeller 30 for the liquid pump, and the intruder in the recess 35 Is to be discharged. For this reason, even when the liquid pump impeller 30 is either in the liquid or in the air, the mass balance can be maintained and the occurrence of vibration can be prevented, so that the occurrence of noise and failure can be prevented. . Further, since the liquid does not accumulate in the recess 35, it is possible to prevent the liquid from leaking from the recess 35 at the time of shipment or transportation.

  In the present embodiment, the discharge port 43 is provided by cutting out the outer peripheral edge of the lid member 40. For this reason, the intruder in the recess 35 can be discharged with a simple structure, and noise and failure can be prevented.

  Furthermore, in this embodiment, the helical channel | path 32 is formed in the inside. For this reason, since it is necessary to provide the large recessed part 35 for weight reduction, the discharge | emission function of an intrusion can be performed still more effectively.

-Modification of Embodiment 1-
In the first embodiment, the rectangular cutouts 42 are provided at three positions on the outer peripheral edge of the lid member 40 with a 120 ° interval. However, the number of the cutouts 42 is not limited to three, It may be increased or decreased. Further, the shape of the notch is not limited to a rectangular shape, and may be a semicircular shape, for example. Furthermore, the outlet may not be a notch in which the opening reaches the outer peripheral end of the lid member, but may be a hole such as an outer circular shape or a rectangular shape in which the opening does not reach the outer peripheral end of the lid member. In short, the notch or the hole may be provided so that the inner end 36a of the seat portion 36 can be seen from the notch or the hole.

(Embodiment 2)
4 and 5 show Embodiment 2 of the present invention, which differs from Embodiment 1 in that the configuration of the discharge port 43 is different. In the present embodiment, the same portions as those in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  That is, the slits 44 parallel to each other are provided in the lid member 40 at, for example, three positions with an interval of 120 °, and the protrusions 45 are formed by pressing between the opposing slits 44 toward the back side (upper side) and projecting. Is formed. By forming the projection 45, a gap is formed between the projection 45 and a portion around the projection 45, and a discharge port 43 for discharging the intruder in the recess 35 is formed by the gap. Has been.

  The discharge port 43 is preferably provided above the inner end 36a of the seat 36 so that the sewage rising along the outer peripheral side wall of the recess 35 can be discharged.

  Therefore, when the submersible pump 1 provided with the liquid pump impeller 30 according to the present embodiment is operated, the same effects as those of the first embodiment can be obtained, and the protrusion 45 exhibits a so-called back spring action. Thus, the pressure on the back side of the liquid pump impeller 30 is improved, and the axial thrust applied to the liquid pump impeller 30 can be reduced.

-Effect of Embodiment 2-
According to the impeller 30 for a liquid pump of the present embodiment, the discharge port 43 is formed by pressing between the opposing slit portions 44 provided in the lid member 40 toward the back side. For this reason, the intruder in the recess 35 can be discharged from the discharge port 43 with a simple configuration to prevent noise and failure, and the axial thrust applied to the liquid pump impeller 30 is reduced by the back spring action. Therefore, the occurrence of a failure can be effectively prevented.

-Modification of Embodiment 2-
In the second embodiment, slit portions 44 parallel to each other are provided in the lid member 40 at three positions with an interval of 120 °. However, the number of facing slit portions 44 is not limited, and the number can be increased or decreased. Also good. Further, the opposed slit portions 44 do not have to be provided in parallel to each other, and may be provided in a square shape, for example. Furthermore, the protrusion 45 may protrude not on the back side but on the front side (lower side).

(Other embodiments)
The present invention may be configured as follows for each of the above embodiments.

  In each of the above-described embodiments, the step portion 37 is provided on the outer periphery of the seat portion 36. However, as shown in FIGS. 6 to 8, the step portion 37 may not be provided. Also in this structure, the same effect as each said embodiment is acquired.

  As described above, the present invention is useful for an impeller for a liquid pump for sucking a liquid such as a submersible pump.

It is sectional drawing which looked at the submersible pump provided with the impeller for liquid pumps concerning Embodiment 1 of this invention from the side. It is a top view of the impeller for liquid pumps. It is the III-III sectional view taken on the line of FIG. It is a top view which shows the impeller for liquid pumps concerning Embodiment 1 of this invention. It is the VV sectional view taken on the line of FIG. It is the FIG. 1 equivalent view of the impeller for liquid pumps concerning other embodiment. FIG. 3 is a view corresponding to FIG. 2 according to another embodiment. It is the VIII-VIII sectional view taken on the line of FIG. 7 concerning other embodiment.

Explanation of symbols

30 Impeller for liquid pump 32 Spiral passage 35 Recess 36 Seat 40 Cover member 42 Notch 43 Discharge port

Claims (4)

A liquid pump impeller in which a concave portion is formed on the back surface and a plate-like lid member covering the concave portion is fixed to a seat portion around the concave portion,
An impeller for a liquid pump, wherein the lid member is provided with a discharge port for discharging the intruder in the recess. The impeller for a liquid pump according to claim 1,
An impeller for a liquid pump, wherein the discharge port is formed by a notch or a hole provided in an outer peripheral edge of the lid member and a seat portion viewed from the notch or the hole. The impeller for a liquid pump according to claim 1,
The discharge port is formed by providing a plurality of sets of slit portions opposed to the lid member, and pressing each of the opposed slit portions against the back side or the front side to project the liquid pump impeller. . In the impeller for liquid pumps according to any one of claims 1 to 3,
An impeller for a liquid pump, characterized in that a spiral passage is formed inside.

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