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CN-114738281-B - Self-balancing axial force multistage pump

CN114738281BCN 114738281 BCN114738281 BCN 114738281BCN-114738281-B

Abstract

The invention relates to a multistage pump capable of self-balancing axial force, which solves the problems of large energy consumption, short service life, poor running stability and the like caused by huge axial force generated by the fact that the external diameter of a front cover plate, a rear cover plate and the like and the specific rotation number ns is more than 300 in the prior art. The self-balancing pump has the advantages that the impeller with the area of the front cover plate being larger than that of the rear cover plate is adopted, and the air guide sleeve is matched, so that the self-balancing of the axial force of the impeller is realized, the pump is more stable and reliable in operation, the power consumption is greatly reduced, the social and economic benefits are greatly improved, and the purposes of energy conservation and emission reduction are achieved.

Inventors

  • SONG WEIWEI
  • LI CHUAN
  • CAO LONGCAI

Assignees

  • 新界泵业(浙江)有限公司

Dates

Publication Date
20260505
Application Date
20220507

Claims (4)

  1. 1. The multistage pump capable of self-balancing axial force comprises a pump body, an impeller string arranged in the pump body, and a plurality of groups of impeller units, wherein one group of impeller units comprises a guide cover, impellers arranged in a guide cavity of the guide cover, the impellers comprise a front cover plate, a rear cover plate and blades arranged between the front cover plate and the rear cover plate, the outer diameter of the front cover plate is larger than that of the rear cover plate, the front cover plate is matched with the bottom of the guide cavity, and the front cover plate is matched with the opening part of the guide cavity; The diameter of the circumcircle of the blade is larger than the outer diameter of the rear cover plate, the diameter of the circumcircle of the blade is smaller than the outer diameter of the front cover plate, and the blade is provided with an extension part at the periphery of the rear cover plate; the specific rotation number ns of the impeller is 80< ns <150; The air guide sleeve comprises an air guide sleeve shell, an annular seat arranged on the back surface of the air guide sleeve shell, an annular cover matched with the annular seat, an impeller annular is arranged at the annular position of the impeller, the impeller annular is arranged in an annular cavity where the annular seat and the annular cover move, and the air guide cavity is arranged in the air guide sleeve shell; the diversion cover shell comprises a diversion part, a lower turnover part, a first transverse turnover part, an upper turnover part and a second transverse turnover part which are of an integrated structure, the diversion part is in a flared waist drum shape, the inner cavity of the diversion part is the diversion cavity, the upper edge of the lower turnover part is matched with the inner edge of the diversion part, the outer edge of the first transverse fold part is matched with the lower edge of the lower folding part, the lower edge of the upper folding part is matched with the inner edge of the first transverse fold part, the outer edge of the second transverse fold part is matched with the upper edge of the upper folding part, and the inner edge of the second transverse fold part is in clearance fit with the outer wall of the impeller mouth ring.
  2. 2. The self-balancing axial force multistage pump according to claim 1, wherein the area ratio S of the front cover plate and the rear cover plate is 0.95≤S≤1.
  3. 3. The multistage pump capable of self-balancing axial force according to claim 1, wherein the cross section of the ring cover is Z-shaped, an upper shoulder of the Z shape is pressed on the upper end face of the impeller ring, a lower shoulder of the Z shape is pressed on the first transverse fold part, and a bevel arm of the Z shape is buckled on the outer side of the upper fold part and forms interference fit with the upper fold part.
  4. 4. A self-balancing axial force multistage pump according to claim 3 wherein said collar cap is a rigid elastically deformable member and said collar seat is a reverse-buckling disk.

Description

Self-balancing axial force multistage pump Technical Field The present invention relates to a multistage pump, and more particularly, to a multistage pump with self-balancing axial force. Background The impeller in the conventional multistage pump adopts a mode that the outer diameters of a front cover plate and a rear cover plate are equal under the influence of the design of the hydraulic performance, and a scheme that the impeller is matched with a guide cover does not exist in each stage corresponding to the multistage pump. For the existing multistage pump, liquid is thrown out of the impeller vertically and enters the pump body or the flow guider under the action of centrifugal force of the impeller. The front cover plate and the rear cover plate with the same outer diameter have unequal cover plate area ratios, so that larger impeller axial force is formed. In particular, for a multistage pump, the maximum number of impellers reaches 40, the accumulated axial force is very large, the service lives of a motor and a bearing are greatly reduced due to the huge axial force, and the operation stability of the pump is poor. In order to balance the axial forces, a dedicated motor must be provided, which in turn increases the cost of the dedicated motor, resulting in a high cost multi-stage pump. Of course, there are also a few single-stage pumps or multistage pumps which use similar impeller structures with unequal front cover plates and rear cover plates (i.e. in such a way that impeller outlets are beveled), and the specific rotation number ns of the hydraulic parameters of these single-stage pumps or multistage pumps is more than 300, and such impellers are also called mixed-flow impellers or diagonal-flow impellers, firstly to obtain larger flow and lower lift, and secondly to eliminate impeller outlet backflow areas and to control secondary backflow of liquid. In summary, the prior art has the following disadvantages: 1. in terms of structural performance, larger axial force is generated, and the bearing load of the motor is required to be consumed in balancing the axial force, so that the energy consumption of the motor is improved; 2. In the aspect of hydraulic performance, the direction of liquid flow is unstable, internal vortex is easy to form, and the hydraulic loss is large, thus being a bottleneck problem in the industry; 3. in terms of comprehensive performance, the energy-saving requirement cannot be met, and the response of the call of the carbon neutralization carbon peak is not facilitated. However, the market share of the existing multistage pump products in the fields of municipal water supply and drainage, secondary water supply, industrial pressurization, sea water desalination and the like exceeds 250 hundred million, and in the national carbon neutral and carbon peak reaching policy context, more proper, reasonable and improved multistage pump products are required to be produced. Disclosure of Invention The invention aims to solve the problems in the prior art and provide a self-balancing axial force multistage pump, which adopts an impeller with a front cover plate area larger than a rear cover plate area, and is matched with a guide cover to realize the self-balancing of the axial force of the impeller, so that the pump can run more stably and reliably, the power consumption is greatly reduced, the social and economic benefits are greatly improved, and the purposes of energy conservation and emission reduction are achieved. The technical aim of the invention is mainly solved by the following technical scheme: the utility model provides a multistage pump of self-balancing axial force, includes the pump body, sets up the impeller cluster in the pump body, impeller cluster a plurality of groups impeller unit is constituteed, its characterized in that a set of impeller unit includes the kuppe, sets up the impeller in the water conservancy diversion chamber of kuppe, the impeller includes front shroud, back shroud and sets up the blade between front shroud and the back shroud, the external diameter of front shroud is greater than the external diameter of back shroud, the front shroud with the bottom cooperation of water conservancy diversion chamber, the front shroud with the open portion position cooperation of water conservancy diversion chamber. The impeller with the area of the front cover plate being larger than that of the rear cover plate is adopted, and the air guide sleeve is matched, so that the self-balancing of the axial force of the impeller is realized, the pump is enabled to run more stably and reliably, the power consumption of the motor is greatly reduced, the social and economic benefits are greatly improved, and the purposes of energy conservation and emission reduction are achieved. As a further improvement and supplement to the technical scheme, the invention adopts the following technical measures: Preferably, in order to better realize self-balancing of axial for