CN111810411A

CN111810411A - Multistage shielding pump with balance disc structure

Info

Publication number: CN111810411A
Application number: CN202010794591.XA
Authority: CN
Inventors: 杨春兰; 邹立莉; 王秀叶; 李海博; 丛培展; 牟纪林
Original assignee: Dalian Hermetic Pump Co ltd
Current assignee: Dalian Hermetic Pump Co ltd
Priority date: 2020-08-10
Filing date: 2020-08-10
Publication date: 2020-10-23

Abstract

The invention relates to the technical field of canned motor pumps, and provides a canned motor pump with a multistage belt balance disc structure, which comprises: a pump head unit, a canned motor unit, and a shaft passing through the pump head unit and canned motor unit; the shield motor unit includes: a stator assembly and a rotor; the stator assembly comprises a motor shell front cover, a motor shell, a stator and a motor shell rear cover; the motor shell front cover and the motor shell rear cover are respectively connected with two ends of the motor shell, and the stator is arranged inside the motor shell; a stator shielding sleeve is embedded in the stator assembly and is respectively welded with the front cover and the rear cover of the motor shell; a rotor shielding sleeve is embedded in the outer circle part of the rotor, rotor shielding plates are respectively embedded at two ends of the rotor, the rotor shielding sleeve and the rotor shielding plates are welded, and the rotor shielding plates are welded with the shaft; the tail end of the shaft is fixed with a balance disc through a key. The invention can well balance the axial force, has strong axial force adjusting capability and stable and reliable operation.

Description

Multistage shielding pump with balance disc structure

Technical Field

The invention relates to the technical field of canned motor pumps, in particular to a canned motor pump with a multistage belt balance disc structure.

Background

The canned motor pump is an important device in the fields of chemical industry, petrochemical industry, chemical fiber, pharmacy, refrigeration, nuclear power and the like. Canned motor pumps are a common body of centrifugal pumps and canned motors. The rotor of the canned motor and the impeller of the centrifugal pump are fixed on the same shaft, the rotor and the stator are separated by the canned sleeve, the rotor rotates in a conveyed medium, and the power of the rotor is transmitted to the rotor through the magnetic field of the stator and then transmitted to the impeller of the canned pump.

At present, more and more users in the industry use multi-stage canned motor pumps, most of multi-stage pumps have more impeller stages and complex blade shapes, axial force superposition generated by each stage of impeller is difficult to balance, the existence of the axial force seriously influences the operation of the pump, and the range of the prior art capable of adjusting the axial force is very small.

Disclosure of Invention

The invention mainly solves the technical problems that the axial force of a multistage shield pump in the prior art is difficult to balance and the adjustment range of the axial force is very small, and provides a multistage shield pump with a balance disc structure, which can well balance the axial force, has strong axial force adjustment capability and is stable and reliable in operation.

The invention provides a multistage shield pump with a balance disc structure, which comprises: a pump head unit, a canned motor unit and a shaft (10) extending through the pump head unit and canned motor unit;

the shield motor unit includes: a stator assembly and a rotor (11); the stator assembly comprises a motor shell front cover (6), a motor shell (7), a stator (8) and a motor shell rear cover (15); the motor shell front cover (6) and the motor shell rear cover (15) are respectively connected with two ends of the motor shell (7), and the stator (8) is arranged inside the motor shell (7); a stator shielding sleeve (9) is embedded in the stator assembly, and the stator shielding sleeve (9) is welded with the motor casing front cover (6) and the motor casing rear cover (15) respectively;

a rotor shielding sleeve (12) is inlaid in the outer circle of the rotor (11), rotor shielding plates (13) are inlaid in two ends of the rotor (11) respectively, the rotor shielding sleeve (12) is welded with the rotor shielding plates (13), and the rotor shielding plates (13) are welded with the shaft (10);

the shaft (10) is a hollow shaft, a balance disc (19) is fixed at the tail end of the shaft (10) through a key, and the pressure at the rear part of the balance disc (19) is communicated with a multistage impeller structure of the pump head unit through the shaft (10); and a dynamic wear-resistant ring (18) is fixed on the balance disc (19).

Preferably, the pump head unit comprises: the device comprises a suction end cover, a pump body (4), a multi-stage impeller mechanism and a plurality of middle section shells (3) which are fixedly connected in sequence; the suction end cover is connected with the front end of the shaft (10), the suction end cover is fixedly connected with the first pump middle section shell (3), and the last pump middle section shell (3) is connected with the pump body (4); each pump middle section shell (3) is correspondingly arranged outside the impeller mechanism; the impeller mechanism comprises an impeller (1) and guide vanes (2) arranged on the impeller (1), and the impeller mechanism is arranged on a shaft (10).

Preferably, the multistage impeller mechanism is provided with an impeller circulating hole (22).

Preferably, the motor housing front cover (6) and the pump head unit are connected with the suction end cover through a pump head penetrating rod (20).

Preferably, a front bearing body (5) and a rear bearing body (16) are arranged in the shielding motor unit;

the front bearing body (5) is fixed on a motor casing front cover (6);

the rear bearing body (16) is fixed on the rear cover (15) of the motor shell, and the static wear-resisting ring (17) is fixed on the rear bearing body (16).

Preferably, the front bearing body (5) and the rear bearing body (16) are respectively provided with circulation holes which are uniformly distributed, and one circulation hole is arranged right above.

Preferably, a pair of sliding bearing assemblies (14) are arranged in the shielding motor unit, and the pair of sliding bearing assemblies (14) are arranged on the shaft (10) and are fixedly connected with the front bearing body (5) and the rear bearing body (16) respectively.

Compared with the prior art, the multistage canned motor pump with the balance disc structure provided by the invention has the following advantages:

the invention is provided with the balance disk, the positions of the impeller of the pump head part and the shaft through hole which are connected with the pressure at the rear part of the balance disk can be adjusted according to the characteristics of the medium and the balance characteristics, and the positions are adjusted to the rear parts of different levels, and the pressure difference generated before and after the balance disk is different, so that the axial force can be adjusted to a greater extent according to the characteristics that the medium is easy to vaporize and is not easy to vaporize and the like and the magnitude of the axial force generated by.

Drawings

FIG. 1 is a schematic structural diagram of a multistage canned motor pump with a balance disc structure provided by the invention;

FIG. 2 is an enlarged fragmentary view of a portion of the pump head of FIG. 1;

fig. 3 is an enlarged view of a portion of the canned motor of fig. 1.

Reference numerals: 1. an impeller; 2. a guide vane; 3. a middle section shell; 4. a pump body; 5. a front bearing body; 6. a motor casing front cover; 7. a motor housing; 8. a stator; 9. a stator shielding sleeve; 10. a shaft; 11. a rotor; 12. a rotor shield sleeve; 13. a rotor shield plate; 14. a sliding bearing assembly; 15. a motor casing rear cover; 16. a rear bearing body; 17. a static wear ring; 18. a dynamic wear ring; 19 a balance disc; 20. the pump head penetrates through the bar; 21. the motor penetrates through the bar; 22. and an impeller circulation hole.

Detailed Description

In order to make the technical problems solved, technical solutions adopted and technical effects achieved by the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some but not all of the relevant aspects of the present invention are shown in the drawings.

FIG. 1 is a flow chart of an implementation of a multistage canned motor pump with a balance disc structure according to an embodiment of the present invention; FIG. 2 is an enlarged fragmentary view of a portion of the pump head of FIG. 1; fig. 3 is an enlarged view of a portion of the canned motor of fig. 1. As shown in fig. 1 to 3, a multistage canned motor pump with a balanced disk structure according to an embodiment of the present invention includes: a pump head unit, a canned motor unit and a shaft 10 extending through the pump head unit and canned motor unit.

The pump head unit comprises: the device comprises a suction end cover, a pump body 4, a multi-stage impeller mechanism and a plurality of middle section shells 3 which are fixedly connected in sequence; the suction end cover is connected with the front end of the shaft 10, the suction end cover is fixedly connected with the first pump middle section shell 3, and the last pump middle section shell 3 is connected with the pump body 4; each pump middle section shell 3 is correspondingly arranged outside the impeller mechanism; the impeller mechanism comprises an impeller 1 and a guide vane 2 arranged on the impeller 1, and the impeller mechanism is arranged on a shaft 10; the multistage impeller mechanism is provided with an impeller circulation hole 22.

The shield motor unit includes: a stator assembly and a rotor 11; the stator assembly comprises a motor shell front cover 6, a motor shell 7, a stator 8 and a motor shell rear cover 15; the motor casing front cover 6 and the motor casing rear cover 15 are respectively connected with two ends of the motor casing 7, and the stator 8 is arranged inside the motor casing 7; stator shield 9 is inlayed in stator module inside, stator shield 9 welds through argon arc welding with motor casing protecgulum 6 and motor casing rear cover 15 respectively, guarantees that shield motor stator module keeps apart with transport medium. The parts of the stator assembly are tightly connected through a motor through bar 21. The motor casing front cover 6 and the pump head unit are connected with the suction end cover through the pump head penetrating bar 20, and the pump head unit is fixed. The shield motor unit is provided with a junction box which is connected with a lead wire of a coil wound on the stator 8.

Rotor 11 excircle position has inlayed rotor housing 12, rotor shield 13 has been inlayed respectively at the both ends of rotor 11, rotor housing 12 welds through argon arc with rotor shield 13, and rotor shield 13 welds with axle 10 argon arc welding, guarantees that rotor 11 keeps apart with transport medium completely.

The shaft 10 is a hollow shaft, a balance disc 19 is fixed at the tail end of the shaft 10 through a key, the pressure at the rear part of the balance disc 19 is communicated with a multistage impeller structure of a pump head unit through the shaft 10 (the multistage impeller structure is provided with an impeller circulating hole 22, the position of the impeller circulating hole 22 communicated with the shaft 10 of the pump head part impeller 1 connected with the pressure at the rear part of the balance disc 19 can be at the rear part of a first-stage impeller, or at the rear parts of a second-stage impeller … … and a third-stage impeller, and the specific position can be given through detailed calculation according to the characteristics and the balance capability of a conveying medium.A dynamic wear-resisting ring 18 is fixed on the balance disc 19 through a screw, and the dynamic wear-.

The shielding motor unit is internally provided with a front bearing body 5 and a rear bearing body 16, the front bearing body 5 is fixed on a motor shell front cover 6 through screws, the rear bearing body 16 is fixed on a motor shell rear cover 15 through screws, circulation holes are respectively formed in the front bearing body 5 and the rear bearing body 16, the circulation holes are uniformly distributed, one circulation hole is required to be positioned right above the circulation hole, and the number and the size of the circulation holes are determined according to the circulation quantity of the shielding motor. The rear bearing body 16 is fixed with a static wear-resistant ring 17 through a screw, and the static wear-resistant ring 17 is a static part. A pair of plain bearing assemblies 14 are mounted internally of the canned motor unit, the pair of plain bearing assemblies 14 being disposed on the shaft 10 and being fixedly connected to the front and

rear bearing bodies

5, 16 respectively.

In the present embodiment, the impeller 1, the shaft 10, the rotor 11, the pair of sliding bearing assemblies 14, the balance disk 19, the dynamic wear ring 18, and the like constitute the rotating components of the multistage canned motor pump. The rotor cavity of the shielding motor unit is filled with a conveying medium, the stator assembly of the shielding motor is isolated from the conveying medium through the stator shielding sleeve 9, and the conveying medium is filled in the stator shielding sleeve 9.

The specific working process of the invention is as follows: the multi-stage canned motor pump rotating component is supported by a pair of sliding bearings 14 and rotates in a conveying medium, most of the conveying medium is pressurized step by a multi-stage impeller mechanism of a pump head unit and discharged from an outlet, a part of the conveying medium enters a gap between a canned motor stator shielding sleeve 9 and a canned motor rotor shielding sleeve 12 through a circulating hole of a front bearing body 5 to cool a canned motor, then enters a pressure cavity at the front part of a balance disk 19 through a circulating hole on a rear bearing body 16, the pressure cavity at the rear part of the balance disk 19 is communicated with a central hole of a shaft 10 and a circulating hole 22 at the impeller part communicated with the shaft 10 of an impeller 1 of the pump head unit, the circulating hole 22 at the impeller part communicated with the pressure cavity at the rear part of the balance disk 19 can be arranged behind a first-stage impeller or behind a second-stage impeller … … which is arranged behind the first-stage impeller, is located after the penultimate stage where the pressure behind the impeller is highest and the pressure differential created across the balance disc 19 is lowest. Therefore, the axial force can be adjusted to a greater extent by adjusting different pressure differences generated at the rear parts of the impellers in different stages according to the characteristics that the conveying medium is easy to vaporize and is not easy to vaporize and the like and the size of the axial force generated by the shield pump.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: modifications of the technical solutions described in the embodiments or equivalent replacements of some or all technical features may be made without departing from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multistage canned motor pump with a balance disc structure, comprising: a pump head unit, a canned motor unit and a shaft (10) extending through the pump head unit and canned motor unit;

2. The multi-stage canned pump with balanced disc structure of claim 1, wherein the pump head unit comprises: the device comprises a suction end cover, a pump body (4), a multi-stage impeller mechanism and a plurality of middle section shells (3) which are fixedly connected in sequence; the suction end cover is connected with the front end of the shaft (10), the suction end cover is fixedly connected with the first pump middle section shell (3), and the last pump middle section shell (3) is connected with the pump body (4); each pump middle section shell (3) is correspondingly arranged outside the impeller mechanism; the impeller mechanism comprises an impeller (1) and guide vanes (2) arranged on the impeller (1), and the impeller mechanism is arranged on a shaft (10).

3. The canned pump with a balance disc structure in multiple stages according to claim 2, wherein the multistage impeller mechanism is provided with impeller circulation holes (22).

4. The multistage canned pump with balance disc structure of claim 1, wherein the motor housing front cover (6) and the pump head unit are connected with the suction end cap by a pump head through bar (20).

5. The multistage canned pump with balanced disc structure according to claim 1, characterized in that inside the canned motor unit are mounted a front bearing body (5) and a rear bearing body (16);

the front bearing body (5) is fixed on a motor casing front cover (6);

6. The multistage canned pump with a balance disc structure according to claim 5, wherein the front bearing body (5) and the rear bearing body (16) are respectively provided with circulation holes, the circulation holes are uniformly distributed, and one of the circulation holes is arranged right above.

7. The multistage canned pump with balanced disc structure according to claim 6, characterized in that the canned motor unit has a pair of plain bearing assemblies (14) mounted inside it, the pair of plain bearing assemblies (14) being arranged on the shaft (10) and being fixedly connected to the front (5) and rear (16) bearing bodies, respectively.