JP5436381B2 - Liquid pump - Google Patents

Description

  The present invention is directed to a centrifugal liquid pump using a closed impeller for liquid sewage mixed with foreign matter, etc., and in particular, the passage of foreign matter etc. of an underwater electric pump used by being submerged in liquid. It is about.

  In the conventional filth pump, which is a submersible motor pump and defined by the number 1414 of the term of JIS B 0131, the pump casing side is connected to the suction side of the closed impeller, which is installed in the pump casing and attached to the outlet end of the pump shaft. A wear ring having a L-shaped cross-sectional shape facing each other with a gap and having a plurality of blade portions formed on the opposite surface side of the horizontal plate is mounted, and the pressure side in the pump casing is caused by the centrifugal action of the blade portions. A submersible electric pump configured to prevent foreign matter blockage and reduction in pump efficiency without increasing the gap by preventing backflow from the surface to the opposite surface portion is known (see, for example, Patent Document 1). .)

  In addition, the annular gap between the outer peripheral edge of the blade (blade) and the inner periphery of the casing, which is stretched from the hub of the axial flow type impeller of the vertical axial pump, the casing is closer to the outlet side of the blade (blade) edge. The driven fluid sucked into the casing by the rotation of the impeller flows as a swirling flow in the casing, and the foreign matter contained in the driven fluid swirls. Since it receives centrifugal force by the flow and moves to the inner peripheral surface side of the casing, foreign matter that has entered between the edge of the blade and the casing is separated from the inner peripheral surface of the casing toward the outlet side of the blade. Therefore, it can easily move to the exit side of the impeller and allow foreign matters to pass through quickly, preventing the biting of foreign matters into the annular gap and preventing tripping of the drive unit due to casing damage or overload. On the other hand, feathers Since many leakage of pumping with the passage of foreign matter on the outlet side of the edge, the configuration of the vertical-shaft axial flow pump pumping performance of the pump is reduced are also known (e.g., see Patent Document 2.).

  Furthermore, in the conventional bladeless pump which is a submersible motor pump and is defined by the number 1325 of the term of JIS B 0131, the outer peripheral surface of the side plate of the closed impeller which is built in the pump casing and attached to the outlet end of the pump shaft. The horizontal planes of both of the inner wall surfaces of the casing opposite to each other are loosely fitted through a narrow annular gap with substantially no level difference, and the outer side surface of the side plate of the impeller and the side wall portion of the casing The opposing space between the two is formed in a stepped gap and loosely fitted to the lower end inner peripheral surface of the casing through a narrow annular gap with the lower end outer peripheral surface of the impeller side plate so as to play a role of a fluid seal In addition, a submersible electric pump configured to prevent entry of foreign matter into the opposing space formed in the stepped gap is known (for example, see Patent Document 3).

Japanese Utility Model Publication No. 61-140197 (Fig. 1-3) Japanese Utility Model Publication No. 7-10495 (Fig. 1-5) Japanese Patent Laying-Open No. 2005-240764 (FIG. 1)

  However, in the conventional filth pump which is the submersible motor pump of Patent Document 1, the stationary pump casing mouse is caused by the pressure difference between the pump casing pumping channel (high pressure side) and the suction channel (low pressure side). In order to prevent intrusion of foreign matter into the facing gap between the ring and the wear ring having an L-shaped cross section attached to the rotating impeller, a plurality of horizontal plates on the wear ring on the inlet side of the facing gap In order to provide a separate blade portion and prevent foreign matter from entering the inlet of the counter gap due to forced counter flow due to centrifugal action, additional load power is required with the swirling of the plurality of blade portions. At the same time, due to the water absorption action associated with the generation of the forced counter flow, the impeller is blocked by the entry or blockage of foreign matter intrusion due to the water absorption from the outlet side of the opposite gap portion of the suction flow path (low pressure side). Restraint In addition to the risk of generating locks, excessive wear, vibration and noise, the pump performance is reduced due to water leakage into the pump casing pumping flow without going through the original impeller water passage. Since the pump performance is low and the load power is large, the pump efficiency is inevitably low.

  Further, in the vertical axial flow pump of Patent Document 2, the foreign matter that has entered between the edge of the blade and the casing is separated from the inner peripheral surface of the casing toward the outlet side of the blade, so that the impeller While moving easily to the outlet side and allowing foreign matter to pass through quickly, the biting of foreign matter is prevented, but on the exit side of the blade edge, which is an important part for pumping performance, the amount of leakage of pumping water increases with the passage of foreign matter. As a result, the pumping performance of the pump is lowered and the pump efficiency is deteriorated.

  Furthermore, in the conventional bladeless pump that is the submersible motor pump of Patent Document 3, the horizontal planes of the inner wall surface of the casing facing the outer peripheral surface of the side plate of the closed impeller are substantially flush with each other in a stepped shape. The facing inner space between the outer surface of the side plate of the impeller and the side wall portion of the casing formed in the gap, the lower end outer circumferential surface of the impeller side plate and the narrow annular gap A fluid seal that is loosely fitted to the outer space prevents foreign matter from entering the opposing space formed in the stepped gap, but a high head or long distance pumping that requires high discharge pumping pressure, etc. Since it is not possible to completely prevent the entry of foreign matter into the opposing space due to backflow at the time of operation or when the operation is stopped, the foreign matter accumulated in the opposing space having a bag path shape without a discharge mechanism, Staircase There is a risk of impeller restraint (locking), excessive wear, vibration and noise due to foreign matter being caught in the gap of this, and labor is required for the above foreign matter removal cleaning The troublesome disassembly and assembling work has to be done frequently, and there is a disadvantage that maintenance costs increase.

  Therefore, in view of the above problems, the present invention greatly reduces the pump efficiency even when there is an operation such as a high head or long distance pumping that requires a high discharge pumping pressure, a backflow due to a long-term operation stoppage, or the like. It can be manufactured at low cost, and there is no impeller restraint (lock) due to foreign matter biting or accumulation of foreign matter, excessive wear due to retention of abrasive particles, and unnecessary disassembly / removal related to foreign matter removal cleaning An object of the present invention is to provide a centrifugal liquid pump using a closed impeller that does not generate maintenance costs such as assembly work and does not generate vibration and noise due to foreign matter.

  To achieve the above object, according to a first aspect of the present invention, there is provided a centrifugal liquid pump using a closed type impeller, wherein a closed impeller mounted in a pump casing is attached to a leading end of the pump shaft. The end surface of the closed impeller side plate in the pump shaft lead-out direction and the suction side end surface of the pump casing in which the foreign material passage groove is formed are opposed to each other through a narrow gap. A suction flow path is formed by opening a suction port, and water from the suction flow path passes through the water passage in the closed impeller, and the impeller from the outer periphery of the closed impeller, which is the terminal opening of the water passage. The side plate and the main plate outer peripheral surface are loosely fitted and surrounded by a pumping flow passage in a pump casing, and are configured to be drained from a discharge opening of a pump casing which is a terminal opening of the pumping flow passage. Above Pong An annular gap is formed between the side plate outer peripheral surface of the closed impeller that is loosely fitted to the inner peripheral surface of the bottom surface of the pumping flow path so as to be wider than the gap on the suction side end surface of the casing, and from the annular clearance. In order to guide the foreign matter sucked into the foreign substance passage groove carved in the suction side end face of the pump casing, the outer peripheral end of the foreign substance passage groove is outward from the outer peripheral edge of the end face of the closed impeller side plate in the pump shaft lead-out direction. And the opposing space between the outer surface of the side plate of the closed impeller and the inner wall of the pump casing is formed as a circulation channel inclined downward so as to be guided to the outer peripheral end of the foreign substance passage groove. Thus, the foreign matter is sucked and discharged from the circulation passage to the low-pressure suction passage through the foreign matter passage groove.

  In the centrifugal type liquid pump using the closed type impeller according to the first aspect of the present invention, the invention according to the second aspect of the present invention is characterized in that the end surface of the side plate of the closed impeller in the pump shaft lead-out direction and the foreign material passage groove are provided. The suction-side end face of the engraved pump casing faces through a narrow gap, and the suction pipe for water absorption is formed with the same diameter so that there is no step on the inner circumference of both end faces. And it is comprised so that it may become substantially flush so that a level | step difference may not be made at the upper end of the said annular clearance.

  In the centrifugal liquid pump using the closed type impeller according to the first aspect of the present invention, the invention according to the third aspect of the present invention is characterized in that the end surface of the side plate of the closed impeller in the pump shaft lead-out direction and the foreign substance passage groove are provided. Make the inner peripheral diameter of the end face of the closed impeller side plate facing the suction side end face of the engraved pump casing through a narrow gap slightly larger, and open the suction port for water absorption A step is formed on the inner peripheral surface of the suction flow path, and the side plate upper surface of the closed impeller outer periphery, which is the terminal opening of the water passage, is slightly higher than the bottom surface of the pump casing in the pumping flow path, A step is formed at the upper end.

  Further, in the centrifugal liquid pump using the closed type impeller according to the second aspect of the present invention, the invention according to the fourth aspect of the present invention is characterized in that the end surface of the side plate of the closed impeller in the pump shaft lead-out direction and the passage of foreign matter. The suction side end face of the pump casing in which grooves are formed are opposed to each other through a narrow gap, and the inner peripheral diameter of the end face of the side plate of the closed impeller is formed to be slightly larger. A step is formed outward from the peripheral surface.

  Further, in the centrifugal liquid pump using the closed impeller according to claim 2 of the present invention, the invention according to claim 5 of the present invention is the terminal opening of the water passage that forms the upper end of the annular gap. The upper surface of the side plate on the outer periphery of the closed impeller is slightly higher than the bottom surface in the pumping flow path of the pump casing so that a step is formed at the upper end of the annular gap.

  Furthermore, in the centrifugal liquid pump using the closed type impeller according to any one of claims 1 to 5, the invention according to claim 6 of the present invention is the circulation channel inclined to the downward gradient. Is formed in an annular recess having a height difference, the foreign material passage groove is formed on the bottom surface of the annular recess, and the outer peripheral edge of the end surface of the side plate of the closed impeller in the pump shaft lead-out direction is wide and circular. The inner peripheral surface of the annular recess is configured so as to face each other through a recessed space.

  In the centrifugal liquid pump using the closed type impeller according to any one of claims 1 to 6, the foreign matter passage groove is formed in the invention according to claim 7 of the present invention. The suction-side end surface portion of the pump casing is configured by a small, separately mountable mouth ring.

  Furthermore, in the centrifugal liquid pump using the closed impeller according to any one of claims 1 to 7, the invention according to claim 8 of the present invention is provided on an inner wall portion of the pump casing. A plurality of guide walls are provided so as to project to the outer peripheral end of the foreign substance passage groove and are formed in a circulation channel inclined downward.

  According to the centrifugal liquid pump using the closed type impeller according to the invention of claim 1, the high pressure side facing the pumping flow path between the stationary pump casing and the rotating impeller as in the prior art Closed impellers do not require the entry of foreign matter from the inlet side of the gap, or the need to allow a foreign object to pass by providing a wide gap between the outer peripheral surface of the impeller and the inner peripheral surface of the pump casing. The end surface of the side plate of the pump shaft in the direction in which the pump shaft is led out and the suction side end surface of the pump casing in which the foreign material passage groove is formed are opposed to each other through a narrow gap and are loosely fitted to the inner peripheral surface of the bottom surface of the pumping flow path in the pump casing A foreign object passage groove formed by engraving foreign matter sucked from the annular gap on the suction side end face of the pump casing, with an annular gap between the opposite peripheral surface of the closed impeller facing wider than that of the suction side end face. Lead to In addition, the outer peripheral end of the foreign material passage groove is extended outward from the outer peripheral edge of the end surface of the closed impeller side plate in the pump shaft lead-out direction, and between the outer side surface of the closed impeller side plate and the inner wall of the pump casing. Is formed in a circulation channel inclined downward so as to be guided to the outer peripheral end of the foreign material passage groove, and the foreign material is transferred from the circulation channel to the low-pressure suction channel via the foreign material passage groove. Since the suction side end face is made a narrow gap, the amount of water leakage to the suction flow path is suppressed, and foreign substances are formed in the annular gap formed wider than the gap. The foreign matter is smoothly guided to the opening at the outer peripheral end of the foreign matter passage groove of the stationary body that is not shielded without being bitten and sucked and discharged into the low-pressure suction passage, and passes through the water passage of the original impeller. Discharge via pump casing pumping channel Because the water is pumped to a high place or a long-distance target place without increasing the load power, it can be driven by high-lift or long-distance pumping that requires high discharge pumping pressure or long-term shutdown. Even in the case of backflow, etc., it is unnecessary because there is no excessive wear due to vibration, noise, impeller restraint (lock), and abrasive particles due to biting or accumulation of foreign matter, etc. without significantly reducing pump efficiency. Excellent closed work that does not require disassembling and assembling work related to troublesome foreign matter removal and cleaning, is easy to maintain, and has a simple structure, good workability, and low manufacturing and maintenance costs. A centrifugal liquid pump using a shaped impeller can be provided.

  According to the centrifugal liquid pump using the closed type impeller according to the second aspect of the present invention based on the first aspect of the present invention, the side plate end face of the closed impeller that forms the suction passage and the suction of the pump casing A suction channel for water absorption is formed with the same diameter so that the inner circumference of both end faces of the side end face cannot be stepped, and a suction flow path is formed, so that the step is not flush with the upper end of the annular gap. Since there is no projection that becomes a resistance by blocking the main flow in the flow path, there is no flow path loss, so that foreign matter can enter the circulation path more smoothly and from the foreign material passage groove. It can be sucked out.

  According to the centrifugal liquid pump using the closed type impeller according to the third aspect of the present invention based on the first aspect of the present invention, the end surface of the side plate of the closed impeller in the pump shaft lead-out direction and the foreign substance passage groove are provided. Make the inner peripheral diameter of the end face of the closed impeller side plate facing the suction side end face of the engraved pump casing through a narrow gap slightly larger, and open the suction port for water absorption A step is formed on the inner peripheral surface of the suction flow path, and the side plate upper surface of the closed impeller outer periphery, which is the terminal opening of the water passage, is slightly higher than the bottom surface of the pump casing in the pumping flow path, Since a step is formed at the upper end, the entrained flow along the flow path wall expanded by the step that expands the flow path in the secondary direction of the flow at the upper end that becomes the entrance of the annular gap The flow of In addition to the action of foreign matter being induced in the wake, foreign matter intrusion from the upper end, which is the entrance of the annular gap, is suppressed, guided to the normal mainstream, and pumped together with pumped water from the discharge port of the pump casing. In the exit portion of the foreign material passage groove on the inner peripheral surface of the suction flow path, the flow of the entrained flow along the flow path wall expanded by the step that expands the flow path in the secondary direction of the flow is generated. Due to the synergistic effect that the negative pressure action of the accompanying flow is applied to the outlet part of the foreign substance passage groove opened in the low-pressure suction channel, the foreign substance that has entered the circulation path can be strongly sucked and discharged from the foreign substance passage groove. Therefore, in addition to the effect of suppressing the entry of foreign matter into the circulation path, the foreign matter that has entered the circulation path can be combined with the respective effects of being strongly sucked and discharged from the foreign matter passage groove.

  According to the centrifugal liquid pump using the closed type impeller according to the invention of claim 4 based on claim 2 of the present invention, the flow is caused at the outlet portion of the foreign substance passage groove on the inner peripheral surface of the suction passage. The flow of the entrained flow along the flow path wall expanded by the step that expands the flow path in the secondary side direction of the secondary gas is generated at the outlet portion of the foreign substance passage groove opened in the low pressure suction flow path. Due to the synergistic effect of the negative pressure action of the flow, the foreign matter that has entered the circulation path can be strongly sucked and discharged from the foreign matter passage groove.

  According to the centrifugal liquid pump using the closed type impeller according to the invention of the fifth aspect based on the second aspect of the present invention, in the upper end portion serving as the inlet of the annular gap, The flow of the entrained flow along the flow path wall expanded by the step that expands the flow path is generated, so that the foreign material intrusion from the upper end portion serving as the inlet of the annular gap is caused by the action of the foreign material being induced in the entrained flow. Suppressed and guided to the normal mainstream, it can be pumped together with pumped water from the outlet of the pump casing.

  According to the centrifugal type liquid pump using the closed impeller according to the invention of claim 6 based on any one of claims 1 to 5 of the present invention, the inner circumference of the circulation channel inclined to the downward gradient is provided. A space that is formed in an annular recess having a height difference, in which the foreign substance passage groove is engraved on the bottom surface in the annular recess, and an outer peripheral edge of the end face of the side plate of the closed impeller in the pump shaft lead-out direction and a wide annular recess Since the inner peripheral surface of the annular recess is configured so as to face each other, the annular recess is turned by turning the outer peripheral side surface of the end surface in the pump shaft derivation direction of the side plate of the closed impeller that forms the annular recess. Due to the strong swirl flow generated inside, the foreign matter is strongly downstream from the circulation channel inclined downward, and is smoothly circulated to the outer opening of the foreign matter passage groove formed on the bottom surface in the annular recess. From the inner outlet of the passage groove to the suction channel Since issued 引排 can be smoothly sucked and discharged without long foreign matter entangled.

  According to the centrifugal type liquid pump using the closed type impeller according to the invention of the seventh aspect based on any one of the first to sixth aspects of the present invention, the suction of the pump casing in which the foreign substance passage groove is engraved. Because the side end surface is composed of a small, separately-mountable mouth ring that can be worn, the amount of the right material and the right amount of the foreign material depending on the quality of the liquid to be pumped and the properties of the foreign matter contained in it. It is extremely easy to cope with a proper mouth ring having a passage groove, and the clearance adjustment of the narrow suction side end surface can be done very easily only by adjusting the mounting of the mouth ring. Even if the moving end surface is worn away and it becomes impossible to form a narrow gap, it is easy to remove only the mouth ring and use it with a highly versatile machine tool such as a general-purpose lathe owned by a town factory. Since it is possible to handle regenerative cutting of the sliding surface of the mouth ring, it is easy to work, including replacement of a new mouth ring, and the cost associated with it is low, so it has the advantage of excellent maintainability. doing.

  According to the centrifugal liquid pump using the closed type impeller according to the invention of claim 8 based on any one of claims 1 to 7 of the present invention, a plurality of guide walls are provided on the inner wall portion of the pump casing. Since it is formed in a circulating flow path that is inclined and descends so as to be guided to the outer peripheral end of the foreign substance passage groove, the circulation is performed by turning the outer surface of the side plate of the closed type impeller that forms the circulating flow path. Due to the swirling flow generated in the flow path, the foreign matter is dispersed on each guide wall and is forcibly guided to the outer opening of the foreign matter passage groove corresponding to each guide wall, and the inside of each foreign matter passage groove. Therefore, it is possible to smoothly disperse and discharge from the opening of each foreign matter passage groove without entanglement of long foreign matters.

It is sectional drawing which showed the structure of the centrifugal liquid pump using the closed type impeller of Example 1 of this invention. It is a principal part expanded sectional view which showed the structure of the centrifugal liquid pump using the closed type impeller of Example 2 of this invention using the detail X part of FIG. It is a principal part expanded sectional view which showed the structure of the centrifugal liquid pump using the closed type impeller of Example 3 of this invention using the detail X part of FIG. It is a principal part expanded sectional view which showed the structure of the centrifugal liquid pump using the closed type impeller of Example 4 of this invention using the detail X part of FIG. FIG. 7 is an enlarged cross-sectional view of a main part showing a configuration of a centrifugal liquid pump using a closed impeller of Example 5 of the present invention with the aid of the detail X part of FIG. 1. FIG. 7 is an enlarged cross-sectional view of a main part showing a configuration of a centrifugal liquid pump using a closed impeller of Example 6 of the present invention with the aid of the detail X part of FIG. 1. FIG. 10 is an enlarged cross-sectional view of a main part showing a configuration of a centrifugal liquid pump using a closed impeller of Example 7 of the present invention with the aid of the detail X part of FIG. 1. It is sectional drawing which showed the structure of the centrifugal liquid pump using the closed type impeller of Example 8 of this invention. It is the cross-sectional arrow figure which showed the example which arranged the foreign material passage groove | channel in the S1-S1 line | wire of FIG. 1 radially. It is the cross-sectional arrow view which showed the example which arranged the foreign material passage groove | channel in the S1-S1 line | wire of FIG. It is the cross-sectional arrow figure which showed the example which arranged the foreign material passage groove | channel in the S1-S1 line | wire of FIG. 1 in the shape of a curve. FIG. 9 is a sectional view taken along line S8-S8 in FIG.

  Hereinafter, as an embodiment of a centrifugal liquid pump using a closed impeller of the present invention, the present invention will be described in detail based on an example of an underwater electric pump with reference to the drawings. Note that the present invention is not limited to the embodiment.

  1 to 12, reference numeral 1 denotes a submersible motor mounted on a centrifugal liquid pump unit 4, and 2 denotes a submersible motor that passes through an oil chamber 3 in which a mechanical seal M is installed and is led into a pump casing 5. A pump casing in which a closed impeller 6 is attached to a leading end of the pump shaft 2 and an end face 7sf of the side plate 7 of the closed impeller 6 in a pump shaft leading direction and a foreign substance passage groove 10 are formed. The suction side end face 5sf of 5 is preferably opposed through a narrow gap G1 of 0.3 mm to 0.8 mm, and a suction inlet 12 for water absorption is opened on the inner periphery of the both end faces 5sf and 7sf. SP is formed, and water from the suction flow path SP passes through the water passage 6p in the closed impeller 6 and passes through the outer periphery of the closed impeller 6 which is the terminal opening 6o of the water passage 6p. Side plate The pumping flow is discharged to the pumping flow path 5p in the pump casing 5 that loosely fits and surrounds the outer peripheral surface of the main plate 8 and is discharged from the discharge opening 5o of the pump casing that is the terminal opening of the pumping flow path 5p. A side plate of the closed impeller 6 which is constituted by a path 5p and is loosely fitted to the inner peripheral surface of the bottom surface 5bf of the pumping flow path 5p so as to be wider than the gap G1 of the suction side end surface 5sf of the pump casing 5. 9 is formed in an annular gap G2 of preferably 1 mm to 2 mm between the outer peripheral surface and one or more foreign objects sucked from the annular gap G2 are engraved on the suction side end face 5sf of the pump casing 5 as shown in FIG. 11, the outer peripheral end of the foreign matter passage groove 10 is directed to the end surface 7 s of the side plate 7 of the closed impeller 6 in the pump shaft lead-out direction. And the opposite space between the outer surface 7o of the side plate 7 of the closed impeller 6 and the inner wall 5i of the pump casing 5 is guided to the outer peripheral end of the foreign material passage groove 10. By forming in the circulation channel 11 inclined in such a downward slope, the foreign material is sucked and discharged from the circulation channel 11 through the foreign material passage groove 10 to the low-pressure suction channel SP. .

  On the basis of the first embodiment, the suction side end surface 5sf of the pump casing 5 in which the end surface 7sf in the direction in which the pump shaft 2 is led out of the side plate 7 of the closed impeller 6 shown in FIGS. The suction flow path SP is formed by opening the suction port 12 for water absorption with the same diameter so that the inner peripheral surfaces of the both end faces 5sf and 7sf are opposed to each other through a narrow gap G1 so that there is no step. The upper end of the annular gap G2 is configured to be substantially flush so that there is no step.

  Based on the first embodiment, the suction side end surface 5sf of the pump casing 5 in which the end surface 7sf of the side plate 7 of the closed impeller 6 shown in FIGS. The inner surface diameter of the end face 7sf of the side plate 7 of the closed impeller 6 is made slightly larger, and the suction channel 12 of the suction channel SP is opened by opening the suction port 12 for water absorption. A step is formed on the inner peripheral surface, and the side plate 7 upper surface 7uf on the outer periphery of the closed impeller 6 that is the terminal opening 6o of the water passage 6p is slightly higher than the bottom surface 5bf in the pumping flow path 5p of the pump casing 5, A step is formed at the upper end of the annular gap G2.

  Based on the second embodiment, the suction of the pump casing 5 in which the end face 7sf in the direction in which the pump shaft 2 is led out of the side plate 7 of the closed impeller 6 and the foreign substance passage groove 10 shown in FIGS. The side end face 5sf is opposed to each other through a narrow gap G1, and the inner peripheral diameter of the end face 7sf of the side plate 7 of the closed impeller 6 is made slightly larger than the inner peripheral face of the suction side end face 5sf of the pump casing 5. A step is formed on the outer side.

  Based on the second embodiment, the upper surface 7uf of the side plate 7 on the outer periphery of the closed impeller 6 that forms the upper end of the annular gap G2 shown in FIGS. 1 and 2 and FIG. The pump casing 5 is configured to be slightly higher than the bottom surface 5bf in the pumping flow path 5p so that a step is formed at the upper end of the annular gap G2.

  Based on any one of the first to fifth embodiments, the inner circumference of the circulation channel 11 inclined to the downward slope of the inner wall 5i of the pump casing 5 shown in FIGS. Formed in the annular recess 13, the foreign material passage groove 10 is formed on the bottom surface 13 uf of the annular recess 13, and has a wide annular shape with the outer peripheral edge of the end surface 7 sf of the side plate 7 of the closed impeller 6 in the direction in which the pump shaft 2 is led out. The inner peripheral surface of the annular recess 13 is configured to face each other through the recessed space.

  Based on any one of the first to sixth embodiments, the suction side end surface portion of the pump casing 5 in which the foreign material passage groove 10 shown in FIGS. The mouse ring 14 is used.

  Based on any one of the first to seventh embodiments, a plurality of guide walls 15 are provided on the inner wall 5i of the pump casing 5 shown in FIGS. It forms in the circulation flow path 11 inclined to the downward slope so that it may guide | induce to.

  Therefore, the effects of the operations described in detail in the effects of the inventions of Nos. 0018 to 0025 can be obtained by the configurations of Embodiments 1 to 8, so that the high lift that requires high discharge pumping pressure, which is the subject of the present invention. It can be manufactured at low cost without reducing the pump efficiency even when there is an operation such as long-distance transportation or back flow due to long-term operation stoppage, etc. Closed type that does not cause excessive wear due to impeller restraint (locking) and retention of wearable particles, and does not require maintenance costs such as disassembly / assembly work related to unnecessary foreign matter removal cleaning, and does not generate vibration or noise due to foreign matter A centrifugal liquid pump using an impeller can be provided.

DESCRIPTION OF SYMBOLS 2 Pump shaft 4 Centrifugal liquid pump part 5 Pump casing 5i Inner side wall of pump casing 5o Pump casing discharge port 5p Pumping flow path in pump casing 5bf Bottom face in pumping flow path 5sf Pump casing suction side end face 6 Closed blade Car 6o End opening of impeller water passage 6p Impeller water passage 7 Impeller side plate 7o Side plate outer surface 7sf Side plate end surface in pump shaft lead-out direction 7uf Side plate upper surface 8 Impeller main plate 10 Foreign material passage groove 11 Circulating flow Channel 12 Suction port 13 of liquid pump part Annular recess 13uf Bottom face 14 in annular recess Mouth ring 15 Guide wall G1 Narrow gap G2 Annular gap SP Suction channel of liquid pump part

Claims (8)

In a centrifugal liquid pump using a closed type impeller, a closed impeller mounted in a pump casing is attached to the outlet end of the pump shaft, and the end surface of the side plate of the closed impeller in the pump shaft outlet direction and a foreign substance passage groove The suction side end face of the pump casing engraved with is opposed to each other through a narrow gap, and a suction passage is formed on the inner periphery of the both end faces to form a suction passage. Water absorption passes through the water passage in the closed impeller, and the pumped flow in the pump casing that loosely fits and surrounds the outer peripheral surface of the impeller from the outer periphery of the closed impeller, which is the terminal opening of the water passage. The pumping flow path is configured to be discharged to the passage and drained from the discharge opening of the pump casing, which is the terminal opening of the pumping flow path, and becomes wider than the gap on the suction side end face of the pump casing. In addition, an annular gap is formed between the outer peripheral surface of the closed impeller that is loosely fitted to the inner peripheral surface of the bottom surface of the pumping flow path, and foreign matter sucked from the annular gap is placed on the suction side end surface of the pump casing. In order to guide to the engraved foreign substance passage groove, the outer peripheral end of the foreign substance passage groove is extended outward from the outer peripheral edge of the end face of the closed impeller side plate in the pump shaft lead-out direction, and the closed impeller side plate outer surface And the inner wall portion of the pump casing is formed in a circulation channel inclined in a downward slope so as to be guided to the outer peripheral end of the foreign material passage groove. A centrifugal liquid pump using a closed impeller characterized in that foreign matter is sucked and discharged to the low-pressure suction passage via The end face of the closed impeller side plate in the pump shaft lead-out direction and the suction casing end face of the pump casing in which the foreign substance passage groove is formed are opposed to each other through a narrow gap so that the inner peripheral surface of the both end faces cannot be stepped. The suction passage for water absorption having the same diameter is opened to form a suction flow path, and is configured to be substantially flush so that there is no step at the upper end of the annular gap. Centrifugal liquid pump using a closed impeller. The end surface of the closed impeller side plate in the pump shaft lead-out direction and the suction side end surface of the pump casing provided with the foreign material passage groove are opposed to each other through a narrow gap, and the inner peripheral diameter of the end surface of the side plate of the closed impeller Is formed in a slightly larger diameter, a suction port for water absorption is opened, a step is formed on the inner peripheral surface of the suction channel, and the upper surface of the side plate on the outer periphery of the closed impeller, which is the terminal opening of the water passage, is formed on the pump casing. 2. The centrifugal liquid using a closed type impeller according to claim 1, wherein a step is formed at the upper end of the annular gap so as to be slightly higher than the bottom surface in the pumping channel. pump. The end surface of the closed impeller side plate in the pump shaft lead-out direction and the suction side end surface of the pump casing provided with the foreign material passage groove are opposed to each other through a narrow gap, and the inner peripheral diameter of the end surface of the side plate of the closed impeller 3. A centrifugal operation using a closed-type impeller according to claim 2, wherein a step is formed outward from the inner peripheral surface of the suction side end surface of the pump casing. Formula liquid pump. The upper surface of the side plate on the outer periphery of the closed impeller that forms the upper end of the annular gap, which is the terminal opening of the water passage, is slightly higher than the bottom surface in the pumping flow path of the pump casing, and a step is formed at the upper end of the annular gap. The centrifugal liquid pump using the closed type impeller according to claim 2, wherein the centrifugal liquid pump is configured to be formed. The inner periphery of the downwardly inclined circulation flow path is formed in an annular recess having a height difference, the foreign substance passage groove is formed in the bottom surface of the annular recess, and the pump shaft of the side plate of the closed impeller is derived. 6. The closed blade according to claim 1, wherein the inner peripheral surface of the annular recess is configured to face the outer peripheral edge of the end face in the direction through a wide annular recessed space. Centrifugal liquid pump using a car. The closed-type blade according to any one of claims 1 to 6, wherein a suction side end surface portion of the pump casing in which the foreign material passage groove is formed is configured by a mouth ring which is a small, separately mountable member. Centrifugal liquid pump using a car. A plurality of guide walls are provided on the inner wall portion of the pump casing so as to be formed in a circulation channel inclined downward so as to be guided to the outer peripheral end of the foreign substance passage groove. A centrifugal liquid pump using the closed type impeller according to any one of the above.

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