JP2019070333A - Submerged pump - Google Patents

Abstract

To provide a submerged pump which prevents clogging in an impeller and wear and damage of blades caused by foreign objects in liquid with a simple structure.SOLUTION: A submerged pump includes: an impeller including a main plate having a front surface and a rear surface and blades fixed to a surface of the main plate; and a casing which houses the impeller and has a surface forming a space with the rear surface of the main plate. The main plate has a penetration passage penetrating through the main plate. An inlet opening of the penetration passage is formed on the rear surface of the main plate and an outlet opening of the penetration passage is formed on the front surface of the main plate. The rear surface of the main plate and the surface of the casing directly face at the radial outer side relative to at least the inlet opening in the space.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a submersible pump.

  Vortex-type pumps, which are generally installed and used in water, have a large distance between the lower edge of the impeller blades and the bottom surface of the pump casing containing the impeller. Therefore, the vortex type pump is widely used as a pump for sewage and filth which can prevent the occurrence of a blockage accident in the pump due to foreign matter.

  The structure of a conventional common vortex pump is shown in FIG. The vortex type pump of FIG. 5 integrally includes a motor unit 2 for driving the main shaft 1 and a pump unit 3 for pumping by rotation of the main shaft 1. The main shaft 1 is sealed with a mechanical seal 4 between the pump unit 3 and the motor unit 2 so that pressure water of the pump unit 3 does not leak to the motor unit 2 side.

  In the motor unit 2, a rotor 5 that rotates integrally with the main shaft 1 and a stator 7 having a stator winding are accommodated in a motor chamber 8. The motor chamber 8 is sealed in a watertight manner by a substantially cylindrical motor frame 10 opened upward and a motor cover 11 connected to the upper end of the motor frame 10, and an underwater cable 12 is connected to the upper portion ing.

  The main shaft 1 is rotatably supported via an upper bearing 13 attached to the motor cover 11 and a lower bearing 15 attached to the inner peripheral surface of the load side bracket 14 connected to the lower end of the motor frame 10. Furthermore, on the upper surface of the motor cover 11, there is provided a handle 16 for suspending or moving the pump to a spring site or the like.

  On the other hand, the pump unit 3 has a plurality of blades 40 and a vortex type pump impeller 41 connected to the end of the main shaft 1 so as to rotate integrally therewith. The pump unit 3 includes a pump casing 50 divided into a lower casing 42 and an intermediate casing 30. The lower casing 42 has a discharge port 42 a and a suction port 42 b and forms a pump chamber 43. The impeller 41 is covered by the lower casing 42, and sucks in water, sewage and the like from the lower part and discharges it from the side surface. The back surface of the impeller 41 is covered by an intermediate casing 30. The discharge curved pipe 24 is connected to the discharge port 42a.

  Between the lower edge of the blade 40 of the impeller 41 and the bottom surface of the lower casing 42, a wide gap C is provided, which is a feature of a vortex type pump, so that even relatively large foreign matter can be discharged easily. It has become. In addition, a pump stand 45 is attached to the lower casing 42 so as to make the pump stand alone.

  The intermediate casing 30 connects the load side bracket 14 and the lower casing 42. The mechanical seal 4 is disposed in a mechanical seal chamber 31 divided by the intermediate casing 30 and the load side bracket 14. The mechanical seal chamber 31 is filled with oil for lubricating and cooling the sliding surface of the mechanical seal.

  The waste water sucked from the suction port 42 b flows radially outward (in other words, the outer peripheral side of the impeller 41) between the blades 40 of the rotating impeller 41. The high-pressure sewage centrifugally applied by the rotation of the impeller 41 collides with the side wall of the pump casing 42 and turns in the axial direction. Thus, a vortex as shown by arrow V in FIG. 5 is formed. The greater the strength of the vortex, the more efficiently the waste water is discharged from the discharge port 42a.

  As mentioned above, the vortex-type pump is configured to form a large gap between the lower surface of the impeller blade and the bottom of the casing so that relatively large foreign matter can be discharged easily.

  However, there is a stagnant vortex region between the suction of the pump casing and the center of the impeller. In the stagnant vortex region, the foreign matter is entangled and lumped, which tends to block the inlet of the flow path between the blades of the impeller. Blockage of the impeller flow path prevents normal operation of the pump. In addition, there is a possibility that the lumped foreign matter may cause wear or breakage of the blades.

  Patent Document 1 proposes mounting a porous strainer in a pump casing in order to prevent wear and breakage of blades caused by foreign matter flowing into the pump casing.

JP-A-9-228978

  According to one embodiment of the present invention, it is possible to provide a submersible pump capable of preventing clogging of the impeller and / or wear and breakage of blades by foreign matter in the liquid by using a simple configuration.

  According to one embodiment of the present invention, there is provided an impeller including a main plate having a front surface and a back surface, and a plurality of blades fixed to the front surface of the main plate, and a casing for housing the impeller, the back surface of the main plate And a casing having a surface forming a space between the main plate and the main plate, wherein the main plate has a through passage extending through the main plate, and an inlet opening of the through passage is formed on the back surface of the main plate An outlet opening of the passage is formed on the surface of the main plate, and a submersible pump is provided in which the back surface of the main plate and the surface of the casing are directly opposed at least radially outside the inlet opening in the space.

  According to one embodiment of the present invention, there is provided an impeller including a main plate having a front surface and a back surface, and a plurality of blades fixed to the front surface of the main plate, and a casing for housing the impeller, the back surface of the main plate And a casing having a surface forming a space between the main plate and the main plate, wherein the main plate has a through passage extending through the main plate, and an inlet opening of the through passage is formed on the back surface of the main plate An outlet opening of the passage is formed on the surface of the main plate, and a plurality of circumferentially spaced back vanes are provided on the surface of the casing at least radially outward of the inlet opening in the space. Thus, a flow path of substantially radially flowing liquid is formed between the plurality of back vanes, and the plurality of back vanes are directed radially inward from the outer side with respect to the rotational direction of the impeller. Extend in the opposite direction , The water pump is provided.

It is sectional drawing which shows the principal part of the submersible pump by 1st Embodiment of this invention. It is the elements on larger scale of FIG. It is the figure which looked at the impeller shown in FIG. 1 from the downward direction, and is a figure which shows arrangement of a penetration way. It is sectional drawing which shows the principal part of the submersible pump by 2nd Embodiment of this invention, and is a figure corresponding to FIG. 2A. It is the figure which looked at the casing shown to FIG. 3A from the downward direction, and is a figure which shows arrangement | positioning of a back blade. It is sectional drawing which shows the principal part of the submersible pump by 3rd Embodiment of this invention, and is a figure corresponding to FIG. 2A. It is the figure which looked at the impeller shown to FIG. 4A from upper direction, and is a figure which shows arrangement | positioning of a boss | hub blade | wing. It is a figure showing an example of the submersible pump by a prior art.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description is merely an example, and the technical scope of the present invention is not limited to the following embodiments. Further, in the drawings, the same or corresponding components are denoted by the same reference numerals, and duplicate descriptions will be omitted. In the following description, terms indicating directions such as “upper” and “lower” mean directions in the installation state of the submersible pump shown in FIG.

  Embodiments of the invention are characterized by the pump section of the submersible pump. Therefore, in the following description, only the components of the pump unit will be described, and the description of the motor unit will be omitted. The configuration of the motor unit of the submersible pump may be any conventionally known configuration other than that described with reference to FIG. Moreover, although the following description demonstrates the pump part of a vortex type | mold pump as an example of a submersible pump, a submersible pump may not be a vortex type pump.

First Embodiment
As shown in FIG. 1, the submersible pump of the first embodiment includes a pump unit including an impeller 141 and a pump casing 150 that accommodates the impeller 141. The pump casing 150 has a discharge port 142a and a suction port 142b, and is formed of a lower casing 142 forming the pump chamber 143 and an intermediate casing 130 fixed to the lower casing 142 by fastening or the like. A motor unit (not shown) is disposed above the intermediate casing 130, and a main shaft driven by the motor unit to rotate the impeller 141 is received and fixed to the boss portion 144 of the impeller 141. The main spindle is not shown in FIG. The motor unit and the pump unit are sealed by a mechanical seal 104 disposed around the main shaft so that pressure water in the pump unit does not leak to the motor unit side.

  FIG. 2A is a partially enlarged view of FIG. As shown in FIG. 2A, the impeller 141 includes a main plate 147 having a front surface 146 and a back surface 148, and a plurality of blades 140 fixed to the front surface 146 of the main plate 147. FIG. 2B is a view of the impeller 141 as viewed from the side of the suction port 142b (downward in FIG. 2A). As shown in FIG. 2B, a plurality of flow paths 140a are formed between the plurality of blades 140 for passing the handling liquid (hereinafter, liquid) of the submersible pump. In FIG. 2B, the arrow R indicates the rotation direction of the impeller 141. As indicated by the arrow F1 in FIG. 1, the liquid flows radially inward from the radially inner side of the impeller 141 and collides with the side wall of the lower casing 142 by the action of centrifugal force due to the rotation of the impeller 141. Change direction in the axial direction. Further, as shown in FIG. 2A, an annular space S around the boss portion 144 exists between the intermediate casing 130 and the back surface 148 of the main plate 147, and one of the high-pressure liquid exiting the outlet of each flow path 140a. The part flows into the space S (indicated by arrow F3 in FIG. 1). The radially inner side of the space S is sealed by a mechanical seal 104. During operation of the submersible pump, a stagnant vortex region as shown by an arrow F2 in FIG. 1 is generated between the suction port 142b and the central portion of the impeller 141.

  According to the first embodiment, the main plate 147 of the impeller 141 has a through passage 149 that penetrates the main plate 147. As shown in FIG. 2A, the through passage 149 has an inlet opening 149 a on the back surface 148 of the main plate 147 and an outlet opening 149 b on the front surface 146. As shown in FIG. 2B, the outlet opening 149 b can open into the area of the flow passage 140 a formed between the vanes 140. The through passage 149 allows the liquid on the back surface 148 side of the main plate 147 to flow to the surface 146 side of the main plate 147 through the through passage 149.

  The number and formation positions of the through passages 149 are not particularly limited, but the outlet opening 149b is preferably formed to be open near the inlet of the flow passage 140a, which is a region which is generally easily blocked by foreign matter. In the example of FIG. 2A, since the region A shown in FIG. 2A is easily clogged with foreign matter, the outlet opening 149b is preferably formed within the range of the dashed line A1-A1 corresponding to the region A.

  As shown in FIG. 2A, the back surface 148 of the main plate 147 and the surface 152 of the pump casing 150 (in the illustrated example, the intermediate casing 130) directly oppose at least the inlet opening 149a in the space S radially outward. Here, “directly opposed” means that the back surface 148 of the main plate 147 and the surface 152 of the pump casing 150 are opposed to each other without a separate member from the main plate 147 and the pump casing 150, such as a liner ring. It means that. Thereby, the back surface 148 of the main plate 147 and the surface 152 of the pump casing 150 define a space that allows substantially radial flow of liquid without locally restricting it. In other words, the back surface 148 and the surface 152 do not include components that locally reduce the separation distance d between them between the outer peripheral edge of the impeller 141 and the inlet opening 149 a of the through passage 149. , Extends. Therefore, the liquid entering the space S is not significantly depressurized before flowing into the inlet opening 149a. In this respect, the through passage 149 of the first embodiment is different from a so-called balance hole conventionally formed in the main plate of the impeller as a means for reducing the axial thrust force acting on the impeller. When a balance hole is formed on the main plate of the impeller, an annular ring, referred to as a liner ring, on at least one of the back surface of the main plate and the surface of the pump casing between the outer peripheral edge of the impeller and the inlet opening of the balance hole. Members or parts of the The liner ring protrudes from the back surface of the main plate and / or the surface of the pump casing and extends in the circumferential direction to locally reduce the separation distance between the back surface of the main plate and the surface of the pump casing in the space S. This limits the amount of liquid that passes through the balance hole and suppresses any drop in pump efficiency that may be caused by the balance hole. Also, the liner ring restricts the radial flow of the liquid so that the pressure of the liquid flowing towards the balance hole is significantly reduced, so that the pressure difference between the inlet and outlet openings of the balance hole As it gets smaller, the flow of liquid through the balance hole is gentle.

  On the other hand, in the first embodiment of the present invention, the flow of the liquid passing through the through passage 149 is actively used to prevent the closure of the impeller 141. Thus, no components are provided to act to reduce the pressure differential between the inlet aperture 149a and the outlet aperture 149b, such as the liner ring described above. At least between the outer peripheral edge of the impeller 141 and the inlet opening 149a of the through passage 149, the back surface 148 of the main plate 147 and the surface 152 of the pump casing 150 are flat (in other words, no unevenness). This can maintain a strong flow of liquid through the through passage 149. Accordingly, stagnation of foreign matter in the stagnant vortex region of the pump chamber 143 and / or blockage of the impeller by foreign matter can be prevented.

  The distance d between the outer peripheral edge of the back surface 148 of the main plate 147 and the surface 152 of the pump casing 150 is preferably set smaller than the diameter of the inlet opening 149 a of the through passage 149. As a result, foreign matter of a size that blocks the through passage 149 can be prevented from entering the back surface 148 side of the main plate 147, so the through passage 149 is not blocked by the foreign matter.

Second Embodiment
FIG. 3A is a view corresponding to FIG. 2A, showing the configuration of the pump unit of the submersible pump according to the second embodiment. The second embodiment differs from the first embodiment in that a plurality of back vanes 132 are provided on the surface 152 of the pump casing 150 (in the illustrated example, the intermediate casing 130). FIG. 3B is a view of the intermediate casing 130 as viewed from the side of the impeller 141 (downward in FIG. 3A). In FIG. 3B, the main shaft of the pump and the mechanical seal 104 disposed in the central opening 130a of the intermediate casing 130 are not shown. As shown in FIG. 3A, on the surface 152 of the intermediate casing 130 facing the back surface 148 of the main plate 147 of the impeller 141, a plurality of back vanes 132 extending substantially perpendicularly to the back surface 148 are attached There is. The back blade 132 is disposed at least between the outer peripheral edge of the impeller 141 and the inlet opening 149a of the through passage 149, and is spaced apart in the circumferential direction as shown in FIG. 3B. The back vane 132 defines a substantially radially flowing liquid flow path 132a to facilitate radial flow of liquid. The arrow R in FIG. 3B indicates the rotation direction of the impeller 141 rotating below the intermediate casing 130. As shown in FIG. 3B, the direction of the back blade 132 is set to a predetermined direction with respect to the rotation direction R of the impeller 141. Specifically, similarly to the blades 140 of the impeller 141, the back blade 132 extends from the radially inner side to the outer side so as to be inclined in the opposite direction with respect to the rotational direction R.

  Thus, with the rotation of the impeller 141, the liquid flowing from the outer peripheral side of the main plate 147 toward the back surface 148 flows radially inward through the flow path 132a between the back vanes 132. As a result, the pressure in the vicinity of the inlet opening 149a of the through passage 149 can be increased, so that the pressure difference between the inlet opening 149a and the outlet opening 149b can be increased. Therefore, the foreign material in the stagnant vortex region of the pump chamber 143 can be pushed out by the strong flow of the liquid flowing through the through passage 149. Accordingly, stagnation of foreign matter in the stagnant vortex region and / or blockage of the impeller by foreign matter can be prevented.

  The back vane 132 may be a separate member from the pump casing 150 or may be a part integrally formed with the pump casing 150.

Third Embodiment
FIG. 4A is a view corresponding to FIG. 2A, showing the configuration of the pump unit of the submersible pump according to the third embodiment. The third embodiment differs from the first embodiment in that a plurality of boss blades 250 are provided as axial flow blades in a boss portion 144 of an impeller 141. The boss portion 144 has a form of a cylindrical portion that protrudes in the axial direction from the back surface 148 of the main plate 147. Although FIG. 4A is a cross-sectional view, only the boss portion 144 is shown in a side view in order to facilitate understanding of the third embodiment. FIG. 4B is a view of the impeller 141 as viewed from the side of the boss portion 144 (upper side of FIG. 4A). The boss blade 250 may be provided to protrude substantially perpendicularly from the outer circumferential surface of the boss portion 144. As shown in FIG. 4B, the bosses 250 can be provided at intervals in the circumferential direction. The plurality of boss vanes 250 define between them a substantially axially flowing liquid flow path 250a to facilitate substantially axial flow of liquid. Arrow R in FIG. 4B indicates the rotational direction of the impeller 141. The direction of the boss blade 250 is set to a predetermined direction with respect to the rotational direction R of the impeller 141. Specifically, the boss blade 250 extends from the back surface 148 side of the impeller 141 toward the mechanical seal 104 so as to incline in the same direction as the rotation direction R. In FIG. 4A and FIG. 4B, reference numeral 251 is attached to the end of the boss blade 250 (in other words, the end on the mechanical seal 104 side).

  According to the third embodiment, it is possible to suppress an excessive pressure rise in the vicinity of the mechanical seal 104 in the space S, and to prevent the liquid in the pump portion from leaking to the motor portion. A high pressure liquid flows into the back surface 148 side of the impeller 141. However, when the back vane 132 is disposed on the intermediate casing 130 as in the second embodiment, for example, the pressure of the liquid in the vicinity of the mechanical seal 104 is still higher It becomes. In the third embodiment, rotation of the boss blade 250 forcibly generates an axial liquid flow passing between the boss blades 250, specifically, a flow from the mechanical seal 104 side toward the inlet opening 149a. Thereby, a pressure difference can be generated between the mechanical seal 104 and the vicinity of the inlet opening 149a.

The boss blade 250 may be a separate member from the boss portion 144 or may be a portion integrally formed with the boss portion 144. Further, axial flow blades such as the boss blade 250 can be provided not on the boss portion 144 but on the surface of the pump casing 150 (the intermediate casing 130 in the illustrated example) facing the outer peripheral surface of the boss portion 144. Also in this case, by adjusting the inclination direction of the blades, it is possible to cause the flow of liquid from the mechanical seal 104 side to the inlet opening 149a.

  As mentioned above, although embodiment of this invention was described, embodiment of the invention mentioned above is for making an understanding of this invention easy, and does not limit this invention. The present invention can be modified and improved without departing from the gist thereof, and the present invention naturally includes the equivalents thereof. In addition, any combination or omission of each component described in the claims and the specification is possible within a range in which at least a part of the above-mentioned problems can be solved, or in a range that exerts at least a part of the effect. It is.

The present invention includes the following aspects.
1. An impeller comprising a main plate having a front surface and a back surface, and a plurality of blades fixed to the front surface of the main plate, and a casing for accommodating the impeller, the surface forming a space between the back surface of the main plate And a casing having a casing, wherein the main plate has a through passage penetrating the main plate, the inlet opening of the through passage is formed on the back surface of the main plate, and the outlet opening of the through passage is formed on the surface of the main plate Submersible pump, wherein the back surface of the main plate and the surface of the casing directly oppose each other radially outward of at least the inlet opening in the space.
2. In the above-described 1., the back surface of the main plate and the surface of the casing are flat at least radially outside the inlet opening in the space. Submersible pump as described in.
3. An impeller comprising a main plate having a front surface and a back surface, and a plurality of blades fixed to the front surface of the main plate, and a casing for accommodating the impeller, the surface forming a space between the back surface of the main plate And a casing having a casing, wherein the main plate has a through passage penetrating the main plate, the inlet opening of the through passage is formed on the back surface of the main plate, and the outlet opening of the through passage is formed on the surface of the main plate A plurality of circumferentially spaced back vanes are provided on the surface of the casing, at least radially outward of the inlet opening in the space, thereby providing a space between the plurality of back vanes. A substantially radially flowing liquid flow path is formed, and the plurality of back vanes extend from the radially inner side to the outer side so as to incline in the opposite direction to the rotational direction of the impeller. ,underwater pump.
4. The separation distance between at least the outer peripheral edge of the back surface of the main plate and the surface of the casing is set smaller than the diameter of the inlet opening of the through passage. Submersible pump according to ~ 3.
5. The main plate includes a boss portion for receiving a main shaft for rotating the impeller, and the boss portion includes a cylindrical portion axially projecting from the back surface of the main plate, and circumferentially on the outer peripheral surface of the cylindrical portion A plurality of spaced apart boss vanes are provided, whereby a substantially axial flow of liquid is formed between the plurality of boss vanes, and the plurality of boss vanes Extending in the same direction as the rotation direction of the impeller in a direction away from the back surface of the main plate, ~ 4. Submersible pump according to any of the.

  The present invention can be widely applied to submersible pumps.

A: Area V: Vortex C: Gap R: Direction of rotation S: Space 1: Main axis 2: Motor section 3: Pump section 4: Mechanical seal 5: Rotor 7: Stator 8: Motor chamber 10: Motor frame 11: Motor cover 12 ... Submersible cable 13 ... Upper bearing 14 ... Load side bracket 15 ... Lower bearing 16 ... Handle 24 ... Discharge curved tube 30 ... Intermediate casing 31 ... Mechanical seal chamber 40 ... Blade 41 ... Impeller 41 ... Lower casing 43 ... Pump chamber 45 ... Pump stand 50: Pump casing 104: Mechanical seal 130: Intermediate casing 130a: Central opening 132: Back blade 132a: Flow path 140: Blade 140a: Flow path 141: Impeller 142: Lower casing 142a: Discharge port 142b: Suction port 143 ... pump chamber 144 ... boss portion 146 ... surface 147 ... main plate 1 48 ... back side 149 ... through passage 149a ... inlet opening 149b ... outlet opening 150 ... pump casing 250 ... boss blade 250a ... flow path 251 ... tip part

Claims (5)

An impeller comprising: a main plate having a front surface and a back surface; and a plurality of blades fixed to the front surface of the main plate;
A casing that accommodates the impeller, the casing having a surface that forms a space with the back surface of the main plate;
A submersible pump comprising
The main plate has a through passage penetrating the main plate, an inlet opening of the through passage is formed on the back surface of the main plate, and an outlet opening of the through passage is formed on the surface of the main plate
The back surface of the main plate and the surface of the casing directly oppose each other radially outward of at least the inlet opening in the space.
underwater pump.   The submersible pump according to claim 1, wherein the back surface of the main plate and the surface of the casing are flat at least radially outward of the inlet opening in the space. An impeller comprising: a main plate having a front surface and a back surface; and a plurality of blades fixed to the front surface of the main plate;
A casing that accommodates the impeller, the casing having a surface that forms a space with the back surface of the main plate;
A submersible pump comprising
The main plate has a through passage penetrating the main plate, an inlet opening of the through passage is formed on the back surface of the main plate, and an outlet opening of the through passage is formed on the surface of the main plate
A plurality of circumferentially spaced back vanes are provided on the surface of the casing radially outward of at least the inlet opening in the space, whereby the space between the plurality of back vanes is provided. To form a flow path for the substantially radially flowing liquid,
The submersible pump, wherein the plurality of back vanes extend from the radially inner side to the outer side so as to be inclined in the opposite direction to the rotational direction of the impeller.   The separation distance between at least the outer peripheral edge of the rear surface of the main plate and the surface of the casing is set smaller than the diameter of the inlet opening of the through passage. Submersible pump. The main plate includes a boss that receives a main shaft that rotates the impeller, and the boss includes a cylindrical portion that protrudes in the axial direction from the back surface of the main plate,
A plurality of boss vanes arranged at intervals in the circumferential direction are provided on the outer peripheral surface of the cylindrical portion, whereby the fluid flowing substantially in the axial direction between the plurality of boss vanes is provided. The flow path is formed,
The submersible pump according to any one of claims 1 to 4, wherein the plurality of boss vanes extend obliquely in the same direction as the rotation direction of the impeller in a direction away from the back surface of the main plate.

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