JP2005240629A

JP2005240629A - Constraint preventing structure of submergible centrifugal pump

Info

Publication number: JP2005240629A
Application number: JP2004049931A
Authority: JP
Inventors: Junko Sakurai; 純子櫻井; Masahiko Fukuda; 正彦福田; Hirohisa Kimura; 啓久木村
Original assignee: Tsurumi Manufacturing Co Ltd
Current assignee: Tsurumi Manufacturing Co Ltd
Priority date: 2004-02-25
Filing date: 2004-02-25
Publication date: 2005-09-08

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constrain preventing structure of a submergible centrifugal pump, not impairing the function of transferring uplift liquid to a height or long distance as a high left pump and not causing biting of foreign matter in sewage. <P>SOLUTION: A very small annular gap 4 is held between the opposite surfaces of the inner peripheral upper part of a pump casing 1 formed concentrically with an interior impeller 2 and the outer peripheral surface of a shroud 3, and a spiral groove 4a extending downward along the rotating direction of the impeller is engraved in both or one of the inner peripheral upper part of the pump casing 1 and the outer peripheral surface of the shroud 3. The foreign matter in uplift liquid sucked into the pump casing 1 is inhibited from entering the annular gap 4 and prevented from a lock accident of the impeller 2 by the downward stream from the spiral groove 4a, and the function of transferring uplift liquid to a height or long distance as a high left pump is not impaired owing to the existence of the small annular gap 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

本発明は、水中遠心ポンプの拘束防止構造に関するものである。 The present invention relates to a restraining prevention structure for a submersible centrifugal pump.

周知のように、水中遠心ポンプでは高揚程化等に伴い、ポンプケーシング内周面と羽根車外周との間に形成される環状間隙（側方クリアランス）が狭められた構造となっている（例えば、特許文献１および２参照。）。しかし、高揚程化等に対応させて側方クリアランスを狭くすれば、汚水中では異物の噛み込みによる羽根車拘束（ロック）事故が問題となる。また、異物の噛み込みを生じさせないため側方クリアランスを大きくすれば、高揚程ポンプとしての揚液の高所或いは長距離移送機能が損われることになる。
特開２０００−１７９４８９号公報（第１−４図）特開２００２−２１７６９号公報（第１図） As is well known, submersible centrifugal pumps have a structure in which an annular gap (side clearance) formed between the inner peripheral surface of the pump casing and the outer periphery of the impeller is narrowed with an increase in head height (for example, And Patent Documents 1 and 2.). However, if the side clearance is made narrower in response to an increase in the head height or the like, an impeller restraint (lock) accident due to the biting of foreign matter becomes a problem in sewage. Further, if the lateral clearance is increased in order not to cause foreign matter to be caught, the height of the pumped liquid or the long-distance transfer function as the high head pump is impaired.
JP 2000-179489 A (Fig. 1-4) Japanese Patent Laid-Open No. 2002-21769 (FIG. 1)

解決しようとする課題は、高揚程ポンプとしての揚液の高所或いは長距離移送機能を損うことなく、しかも汚水中における異物の噛み込みを生じさせることのない、水中遠心ポンプの拘束防止構造を提供することである。 The problem to be solved is a structure for preventing restraint of a submersible centrifugal pump that does not impair the height or long-distance transfer function of the pumped liquid as a high-lift pump and does not cause foreign matter to be caught in sewage. Is to provide.

本発明では、ポンプケーシングの内周面上方部と、前記羽根車のシュラウド外周面との対向面間に狭小な環状間隙を保有させ、ポンプケーシングの内周面上方部および羽根車のシュラウド外周面の双方またはいずれか一方に羽根車の回転方向に沿って巻き下がる螺子溝が刻設されていることを、最も主要な特徴とする。 In the present invention, a narrow annular gap is held between the upper surface of the inner peripheral surface of the pump casing and the outer surface of the shroud of the impeller, and the upper portion of the inner surface of the pump casing and the outer surface of the shroud of the impeller. The most main feature is that screw grooves that are rolled down along the rotation direction of the impeller are engraved in both or any one of the above.

本発明によれば、ポンプケーシング内へ吸込まれた揚液中の異物が、ポンプケーシングの内周面上方部と羽根車のシュラウド外周面との対向面間の環状間隙に入り込もうとしても、該環状間隙に下方向の流れが生じることによって、異物の噛み込みによる羽根車の拘束（ロック）事故を起すことがなく、また、環状間隙は狭小に形成されているため、高揚程ポンプとしての揚液の高所或いは長距離移送機能が損われることもない。 According to the present invention, even if foreign matter in the pumped liquid sucked into the pump casing tries to enter the annular gap between the upper surface of the inner surface of the pump casing and the outer surface of the shroud of the impeller, The downward flow in the annular gap does not cause an impeller restraint (lock) accident due to the inclusion of a foreign object, and the annular gap is formed narrow, so that the pump as a high head pump is lifted. The height of the liquid or the long distance transfer function is not impaired.

内装される羽根車と同心状に形成されたポンプケーシングの内周面上方部と、前記羽根車のシュラウド外周面との対向面間に狭小な環状間隙を保有させ、羽根車のシュラウド外周面には、羽根車の回転方向に沿って巻き下がる螺子溝を刻設する。 A narrow annular gap is held between the upper part of the inner peripheral surface of the pump casing formed concentrically with the impeller to be installed, and the shroud outer peripheral surface of the impeller, and the shroud outer peripheral surface of the impeller is retained. Engraves a screw groove that rolls down along the rotational direction of the impeller.

図１および図２において、１はポンプケーシングであり、内装される羽根車２と同心状に形成された内周面を有している。羽根車２のシュラウド３は、外周面がポンプケーシング１の内周面上方部と狭小な環状間隙４を保って対向し、該シュラウド３の外周面には、羽根車２の回転方向に沿って巻き下がる螺子溝４ｓが刻設されている。５・・５は羽根板、６はポンプケーシング１の下壁中央に開設された吸込口、７はポンプケーシング１の側壁の一側部に開設された吐出口である。この構造により、水中遠心ポンプの運転時、吸込口６からポンプケーシング１内へ吸込まれた揚液中の異物が、前記環状間隙４内に入り込もうとしても、該シュラウド３の外周面に刻設された螺子溝４ｓによって下方向の流れが生じているため、異物の侵入は阻止せられ、異物の噛み込みによる羽根車２の拘束（ロック）事故を起すことなく、異物はポンプケーシング１内を一巡して吐出口７から揚液と共に揚送される。また、環状間隙４は狭く形成されているため、高揚程ポンプとしての揚液の高所或いは長距離移送機能が損われることはない。 1 and 2, reference numeral 1 denotes a pump casing, which has an inner peripheral surface formed concentrically with an impeller 2 to be installed. The shroud 3 of the impeller 2 is opposed to the upper portion of the inner peripheral surface of the pump casing 1 while maintaining a narrow annular gap 4. The shroud 3 is opposed to the outer peripheral surface of the shroud 3 along the rotation direction of the impeller 2. A screw groove 4s to be wound is engraved. 5 and 5 are blades, 6 is a suction port established in the center of the lower wall of the pump casing 1, and 7 is a discharge port established on one side of the side wall of the pump casing 1. With this structure, during operation of the submersible centrifugal pump, foreign matter in the pumped liquid sucked into the pump casing 1 from the suction port 6 is engraved on the outer peripheral surface of the shroud 3 even if it enters the annular gap 4. Since the downward flow is generated by the threaded groove 4s, the intrusion of the foreign matter is prevented, and the foreign matter enters the pump casing 1 without causing a restraint (locking) accident of the impeller 2 due to the biting of the foreign matter. It goes round and is pumped together with the pumped liquid from the discharge port 7. Further, since the annular gap 4 is formed narrow, the height of the pumped liquid or the long distance transfer function as a high head pump is not impaired.

図３および図４において、１はポンプケーシングであり、内装される羽根車２と同心状に形成された内周面を有しており、該内周面の上方部と羽根車２のシュラウド３の外周面とは狭小な環状間隙４を保って対向し、且つ、ポンプケーシング１の内周面上方部には羽根車２の回転方向に沿って巻き下がる螺子溝４ｓが刻設されている。５・・５はシュラウド３の下面に配設された羽根板、６はポンプケーシング１の下壁中央に開設された吸込口、７はポンプケーシング１の側壁の一側部に開設された吐出口である。この構造により、水中遠心ポンプの運転時、吸込口６からポンプケーシング１内へ吸込まれた揚液中の異物が、前記環状間隙４内に入り込もうとしても、ポンプケーシング１の内周面上方部に刻設された螺子溝４ｓによって下方向の流れが生じているため、異物の侵入は阻止せられ、異物の噛み込みによる羽根車２の拘束（ロック）事故を起すことなく、異物はポンプケーシング１内を一巡して吐出口７から揚液と共に揚送される。また、環状間隙４は狭く形成されているため、高揚程ポンプとしての揚液の高所或いは長距離移送機能が損われることはない。 3 and 4, reference numeral 1 denotes a pump casing, which has an inner peripheral surface formed concentrically with the impeller 2 installed therein, and an upper portion of the inner peripheral surface and a shroud 3 of the impeller 2. A screw groove 4 s is formed in the upper portion of the inner peripheral surface of the pump casing 1 so as to be rolled down along the rotational direction of the impeller 2. 5... 5 are vanes disposed on the lower surface of the shroud 3, 6 is a suction port opened in the center of the lower wall of the pump casing 1, and 7 is a discharge port opened on one side of the side wall of the pump casing 1. It is. Due to this structure, when the submerged centrifugal pump is in operation, foreign matter in the pumped liquid sucked into the pump casing 1 from the suction port 6 will enter the annular gap 4, and the upper part of the inner peripheral surface of the pump casing 1 Since the downward flow is generated by the screw groove 4s engraved in the foreign matter, the intrusion of foreign matter is prevented, and the foreign matter is prevented from being caught in the pump casing without causing the impeller 2 to be locked (locked). It goes around the inside of 1 and is pumped together with pumped liquid from the discharge port 7. Further, since the annular gap 4 is formed narrow, the height of the pumped liquid or the long distance transfer function as a high head pump is not impaired.

図５および図６において、１はポンプケーシングであり、内装される羽根車２と同心状に形成された内周面を有しており、該内周面の上方部と羽根車２のシュラウド３の外周面とは狭小な環状間隙４を保って対向し、且つ、該対向するシュラウド３の外周面およびポンプケーシング１の内周面上方部には羽根車２の回転方向に沿って巻き下がる螺子溝４ｓ，４ｓがそれぞれ刻設されている。５・・５はシュラウド３の下面に配設された羽根板、６はポンプケーシング１の下壁中央に開設された吸込口、７はポンプケーシング１の側壁の一側部に開設された吐出口である。この構造により、水中遠心ポンプの運転時、吸込口６からポンプケーシング１内へ吸込まれた揚液中の異物が、前記環状間隙４内に入り込もうとしても、ポンプケーシング１の内周面上方部および羽根車２のシュラウド３の外周面に刻設された螺子溝４ｓによって下方向の流れが生じているため、異物の侵入は阻止せられ、異物の噛み込みによる羽根車２の拘束（ロック）事故を起すことなく、異物はポンプケーシング１内を一巡して吐出口７から揚液と共に揚送される。また、環状間隙４は狭く形成されているため、高揚程ポンプとしての揚液の高所或いは長距離移送機能が損われることはない。 In FIGS. 5 and 6, reference numeral 1 denotes a pump casing having an inner peripheral surface formed concentrically with the impeller 2 to be installed, and an upper portion of the inner peripheral surface and a shroud 3 of the impeller 2. A screw which is opposed to the outer peripheral surface of the shaft 2 while maintaining a narrow annular gap 4, and is wound down along the rotation direction of the impeller 2 on the outer peripheral surface of the facing shroud 3 and the inner peripheral surface of the pump casing 1. Grooves 4s and 4s are formed respectively. 5... 5 are vanes disposed on the lower surface of the shroud 3, 6 is a suction port opened in the center of the lower wall of the pump casing 1, and 7 is a discharge port opened on one side of the side wall of the pump casing 1. It is. Due to this structure, when the submerged centrifugal pump is in operation, foreign matter in the pumped liquid sucked into the pump casing 1 from the suction port 6 will enter the annular gap 4, and the upper part of the inner peripheral surface of the pump casing 1 Since the downward flow is generated by the screw groove 4s engraved on the outer peripheral surface of the shroud 3 of the impeller 2, the entry of foreign matter is prevented, and the impeller 2 is restrained (locked) by the foreign matter being caught. Without causing an accident, the foreign matter travels through the pump casing 1 and is pumped from the discharge port 7 together with the pumped liquid. Further, since the annular gap 4 is formed narrow, the height of the pumped liquid or the long distance transfer function as a high head pump is not impaired.

図１ないし図６の構成を前提として、羽根車２の羽根板５・・５は図７に示すよう、先端部５ｅの肉厚を薄くし該先端部５ｅにおける外周長さ５ａが可能な限り短くなるよう構成する。この構成により、異物は羽根板５・・５の回転後方側へ逃がされることになり、実施例１ないし３における螺子溝４ｓにより発生する下方向の水流の作用とが相俟って、異物の噛み込みによる羽根車２の拘束（ロック）事故防止効果が一層高められる。また、狭い環状間隙４の存在により、高揚程ポンプとしての揚液の高所或いは長距離移送が有効に機能することについても、実施例１ないし３の場合と同じである。 As shown in FIG. 7, the blades 5... 5 of the impeller 2 are made thin in the tip portion 5e so that the outer peripheral length 5a of the tip portion 5e is as long as possible. Configure to be shorter. With this configuration, foreign matter is released to the rotational rear side of the blades 5.. 5, and coupled with the action of the downward water flow generated by the screw groove 4 s in the first to third embodiments, The effect of preventing the impeller 2 from being locked (locked) by biting is further enhanced. In addition, the presence of the narrow annular gap 4 effectively functions for the high-pump or long-distance transfer of the pumped liquid as the high-lift pump as in the case of the first to third embodiments.

本発明構造を備えた水中遠心ポンプの要部縦断側面図であって、羽根車の回転方向に沿って巻き下がる螺子溝が、羽根車シュラウドの外周面に刻設されている事例を示す。It is a principal part vertical side view of the submersible centrifugal pump provided with the structure of this invention, Comprising: The screw groove | channel which winds down along the rotation direction of an impeller is shown in the example by which the outer peripheral surface of the impeller shroud was engraved. 図１の要部拡大図である。It is a principal part enlarged view of FIG. 本発明構造を備えた水中遠心ポンプの要部縦断側面図であって、羽根車の回転方向に沿って巻き下がる螺子溝が、ポンプケーシングの内周面上方部に刻設されている事例を示す。It is a principal part vertical side view of the submersible centrifugal pump provided with the structure of the present invention, and shows an example in which a screw groove that rolls down along the rotation direction of the impeller is engraved in the upper part of the inner peripheral surface of the pump casing. . 図３の要部拡大図である。It is a principal part enlarged view of FIG. 本発明構造を備えた水中遠心ポンプの要部縦断側面図であって、羽根車の回転方向に沿って巻き下がる螺子溝が、羽根車シュラウドの外周面およびポンプケーシングの内周面上方部にそれぞれ刻設されている事例を示す。FIG. 3 is a longitudinal sectional side view of an essential part of the submersible centrifugal pump having the structure of the present invention, and screw grooves that are rolled down along the rotation direction of the impeller are respectively formed on the outer peripheral surface of the impeller shroud and the upper portion of the inner peripheral surface of the pump casing. An example of engraving is shown. 図５の要部拡大図である。It is a principal part enlarged view of FIG. 本発明構造における羽根車の要部底面図である。It is a principal part bottom view of the impeller in a structure of this invention.

Explanation of symbols

１ポンプケーシング
２羽根車
３シュラウド
４環状間隙
４ｓ螺子溝
５羽根板
５ａ外周長さ
５ｅ羽根板先端部 DESCRIPTION OF SYMBOLS 1 Pump casing 2 Impeller 3 Shroud 4 Annular gap 4 s Screw groove 5 Blade plate 5a Outer peripheral length 5e Blade plate tip

Claims

A narrow annular gap is held between the upper part of the inner peripheral surface of the pump casing formed concentrically with the impeller to be installed, and the outer surface of the shroud of the impeller, and the upper inner peripheral surface of the pump casing. A structure for preventing restraint of a submerged centrifugal pump, wherein a screw groove that is rolled down along the rotation direction of the impeller is formed in both or one of the outer peripheral surface of the shroud and the shroud of the impeller.

2. The structure for preventing restraint of an underwater centrifugal pump according to claim 1, wherein the impeller blade plate is configured such that the thickness of the tip end portion is reduced and the outer peripheral length of the tip end portion is shortened.