High-pressure low-temperature vertical multi-stage shield pump using medium as motor jacket cooling water
By adopting a medium circulation cooling system and high-pressure design in the shielded pump, the problem of unstable pump operation under extreme operating conditions is solved, and stable operation and safety of high pressure and low temperature are achieved.
Patent Information
- Application Number
- CN202420401400.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-04
- Publication Date
- 2025-02-18
- Estimated Expiration
- 2034-03-04
AI Technical Summary
In extreme operating conditions, existing shielded pumps are difficult to meet the problems of extremely low media temperature, high vaporization pressure and freezing of cooling water, resulting in unstable pump operation.
High-voltage low-temperature vertical multi-stage shielding pump using medium as motor jacket cooling water, realizes dual cooling of the motor through the circulating cooling system of the medium in the pump head unit and the shielding motor unit, and prevents the medium through high-voltage design and auxiliary impeller mechanism. Vaporization.
The shielded pump is able to operate stably under extreme operating conditions, avoid cooling water freezing, meet the design requirements of high pressure and low temperature, and improve the safety and sealing of the pump.
Smart Images
Figure CN222509039U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a shielded pump technology, in particular to a high-pressure and low-temperature vertical multi-stage shielded pump which utilizes a medium as cooling water for a motor jacket. Background Art
[0002] Canned pumps are important equipment in the fields of chemical industry, petrochemical industry, chemical fiber, pharmaceutical industry, refrigeration and nuclear power. Canned pumps are a combination 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 a shielding sleeve. The rotor rotates in the medium being transported, and its power is transferred to the rotor through the stator magnetic field, and then to the impeller of the canned pump.
[0003] In some special working conditions, such as large flow and head, low medium viscosity, extremely low medium temperature, extremely high medium vaporization pressure, and the medium vaporization pressure curve is particularly affected by temperature changes. This requires the selection of a vertical multi-stage canned motor pump with large power, impeller diameter, and inlet and outlet diameters, and the motor temperature rise requirements are relatively strict. In addition, since the medium temperature is extremely low, the motor jacket will directly pass cooling water, which will cause the cooling water to freeze. In addition, since the vaporization pressure of the medium is relatively high, the canned motor pump itself requires a high-pressure design. The existing design structure cannot meet the working conditions. Utility Model Content
[0004] The purpose of the utility model is to solve the problem that existing canned motor pumps cannot meet the requirements of extreme working conditions, and to propose a high-pressure, low-temperature vertical multi-stage canned motor pump that uses a medium as cooling water for a motor jacket. The canned motor pump has stable and reliable operation and is suitable for extreme working conditions where the flow rate and head are relatively large, the medium viscosity is relatively small, the medium temperature is extremely low, the medium vaporization pressure is particularly high, and the medium vaporization pressure curve is particularly significantly affected by temperature changes.
[0005] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a high-pressure and low-temperature vertical multi-stage canned pump using a medium as cooling water for a motor jacket, comprising: a pump head unit, a canned motor unit, and a shaft penetrating the pump head unit and the canned motor unit;
[0006] The pump head unit comprises: a pump jacket, a suction end cover, a multi-stage impeller mechanism, a plurality of middle section shells fixedly connected in sequence, an axial force balancing mechanism, a pump body, an auxiliary impeller mechanism and a connecting section; the suction end cover is fixedly connected to the first pump middle section shell, the last pump middle section shell is connected to the pump body, the side of the pump body away from the middle section shell is connected to the connecting section, each pump middle section shell is correspondingly arranged outside the impeller mechanism, the pump body is arranged outside the axial force balancing mechanism, and the connecting section is arranged outside the auxiliary impeller mechanism; the impeller mechanism and the auxiliary impeller mechanism are both installed on the shaft;
[0007] The shielded motor unit comprises: a stator assembly and a rotor; the stator assembly comprises a motor housing assembly, a stator and a motor housing rear cover; the motor housing assembly comprises an outlet, an inner shell, an outer shell, a motor housing front flange, a motor housing rear flange and a terminal box seat; the outer shell is provided with an outlet, the stator is provided inside the inner shell, and the motor housing rear cover is connected to the motor housing rear flange; a stator shielding sleeve is inlaid inside the stator assembly, and the stator shielding sleeve is welded to the motor housing front flange and the motor housing rear cover respectively; a rotor shielding sleeve is inlaid on the outer circumference of the rotor, rotor shielding plates are inlaid on both ends of the rotor respectively, the rotor shielding sleeve is welded to the rotor shielding plate, and the rotor shielding plate is welded to the shaft; a rear bearing body is installed on the motor housing rear cover;
[0008] A motor cooling cavity is formed between the inner shell and the outer shell of the motor casing. A motor casing front flange circulation hole connecting the pump body outlet and the motor cooling cavity is provided on the front flange of the motor casing, and the end of the motor cooling cavity away from the pump body outlet is connected to the outlet; a shielded motor cooling gap is provided between the stator shielding sleeve and the rotor shielding sleeve, a connecting section circulation hole connecting the pump body outlet and the chamber where the auxiliary impeller mechanism is located is provided on the connecting section, and the chamber where the auxiliary impeller mechanism is located is connected to the shielded motor cooling gap, and a rear bearing body circulation hole connecting the shielded motor cooling gap and the outlet is provided on the rear bearing body.
[0009] The sizes of the circulation holes in the front flange of the motor housing, the circulation holes in the connecting section and the circulation holes in the rear bearing body are comprehensively determined according to the circulation volume of the shielded motor, the temperature rise of the motor and the vaporization pressure curve of the medium.
[0010] Furthermore, the multi-stage impeller mechanism includes but is not limited to 2-6 stages.
[0011] Furthermore, the shaft is provided with an axial force balancing circulation hole on one side of the impeller, which cooperates with the axial force balancing mechanism to balance the axial force.
[0012] Furthermore, the auxiliary impeller mechanism includes an auxiliary impeller and an auxiliary wear-resistant ring installed on the front flange of the motor housing.
[0013] Furthermore, a stopper and an O-ring seal are provided between the suction end cover and the pump jacket. The suction end cover and the pump jacket are of stopper matching type, and an O-ring seal is added to prevent the medium from flowing back.
[0014] Furthermore, the impeller mechanism includes an impeller and guide vanes arranged on the impeller.
[0015] Furthermore, the axial force balancing mechanism includes a wear-resistant ring installed on the last-stage impeller, a balancing ring seat installed on the connecting section, and a balancing ring installed on the balancing ring seat.
[0016] Furthermore, a reinforcement sleeve is installed on the outer side of the stator shielding sleeve.
[0017] Furthermore, a sliding bearing is installed on the connecting section; and a sliding bearing is installed on the rear bearing body.
[0018] Furthermore, the outlet, the inner shell, the outer shell, the motor housing front flange, the motor housing rear flange and the junction box seat are integrated into one by welding.
[0019] The utility model has a working principle of a high-pressure and low-temperature vertical multi-stage shielded pump that uses a medium as cooling water for a motor jacket: the rotating parts of the multi-stage shielded pump are supported by a pair of sliding bearings and rotate in the conveying medium. Most of the conveying medium is pressurized step by step through the multi-stage impeller mechanism of the pump head unit and discharged from the pump body outlet. A stopper is provided between the suction end cover and the pump jacket to cooperate with an O-ring seal to prevent the high-pressure medium from flowing back to the inlet and affecting the circulation of the medium. Most of the medium flows through the motor housing front flange circulation hole in the motor housing front flange to the motor cooling cavity between the inner shell and the outer shell of the motor housing to cool the motor and flows out from the outlet; a part of the medium discharged from the pump body outlet also flows to the auxiliary impeller through the connecting section circulation hole in the connecting section, and then flows into the rotor cavity under pressure through the auxiliary impeller, and then cools the shielded motor through the gap between the stator shielding sleeve and the rotor shielding sleeve, and then flows to the outlet through the circulation hole on the rear bearing body, and at the same time completes automatic exhaust and is discharged from the exhaust valve at the highest point of the whole pump.
[0020] The utility model uses a medium as a motor jacket cooling water, and the high-pressure and low-temperature vertical multi-stage shielded pump comprises: a pump head unit, a shielded motor unit, and a shaft that penetrates the pump head unit and the shielded motor unit. The pump head unit comprises: a pump jacket, a suction end cover, a multi-stage impeller mechanism, a plurality of middle section shells that are fixedly connected in sequence, an axial force balancing mechanism, a pump body, an auxiliary impeller mechanism, a connecting section, etc. The shielded motor unit comprises: a stator assembly and a rotor; the stator assembly comprises a motor housing assembly, a stator and a motor housing rear cover; the motor housing assembly comprises an outlet, an inner shell, an outer shell, a motor housing front flange, a motor housing rear flange and a terminal box seat, and the six parts are integrated into one by welding, and during the operation of the pump, the space between the inner and outer shells is filled with a low-temperature medium, wherein the inner shell bears the external pressure of the medium, and the outer shell bears the internal pressure of the medium; the stator is arranged inside the motor housing and is encapsulated by the motor housing rear cover; a stator shielding sleeve is inlaid inside the stator assembly, and the stator shielding sleeve is respectively welded to the motor housing front flange and the motor housing rear cover; a rotor shielding sleeve is inlaid on the outer circle of the rotor, and rotor shielding plates are respectively inlaid at both ends of the rotor, the rotor shielding sleeve is welded to the rotor shielding plate, and the rotor shielding plate is welded to the shaft. The pump head unit and the shielded motor unit are connected together by fastening bolts of the connecting section and the front flange of the motor housing; the pump head unit and the shielded motor unit are sealed in the form of a stopper of the pump jacket and the front flange of the motor housing and a sealing gasket, and are fastened by bolts to ensure that the medium inside the pump does not leak. The utility model can ensure that the shielded motor power and temperature rise meet the user's needs without separately setting cooling water, and the operation is stable and reliable.
[0021] The utility model does not need to set up a separate motor jacket cooling water pipeline, which prevents the cooling water from freezing. The motor is cooled directly by high-pressure and low-temperature medium, which controls the temperature rise of the motor very well and can meet the user's demand for power. In traditional designs, due to the special structure of the shielded pump, the internal medium is most likely to vaporize in the motor. The utility model adds an auxiliary impeller mechanism at the front end where the medium enters the rotor cavity, further increasing the pressure in the rotor cavity and effectively preventing the vaporization of the medium in the rotor cavity. The pressure-bearing boundary of the entire pump adopts a high-pressure design to ensure the safety of the operation of the entire pump and leakage-free sealing.
[0022] The utility model shielded pump operates stably and reliably, and is suitable for extreme working conditions where the flow and head are relatively large, the medium viscosity is relatively small, the medium temperature is extremely low, the medium vaporization pressure is particularly high, and the medium vaporization pressure curve is particularly affected by temperature changes. The maximum flow of the utility model shielded pump can reach 400m 3 / h, the maximum head can reach 800m, and the medium viscosity can be lower than 0.1mm 2 / s, the medium temperature can be as low as -100℃.
[0023] The utility model is at least applicable to media with a vaporization pressure greater than 1.2 MPa.
[0024] The utility model can perform dual cooling on the motor through the gap between the stator and rotor shielding sleeves and the low-temperature medium between the inner and outer shells of the motor housing. This structural feature makes the temperature of the stator winding well controlled, and the temperature difference between the upper and lower chambers of the rotor is very small (normal medium will be heated by the motor after passing through the gap between the stator and rotor shielding sleeves). This structure is particularly suitable for low-temperature media with very small temperature rise and large vaporization pressure increase, and is also closely related to the flow rate given by the user system. Because the medium enters between the inner and outer shells of the motor through the circulation hole 15 on the front flange of the motor housing to cool the motor, specific thermal balance calculation and analysis are required for specific working conditions. The cooling effect and temperature control can be adjusted by changing the aperture or number of the circulation holes 15 and the size of the gap between the inner and outer shells of the motor. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 The utility model provides a structural schematic diagram of a high-pressure, low-temperature vertical multi-stage shielded pump which can utilize a medium as cooling water for a motor jacket.
[0026] Figure 2 yes Figure 1 A partial enlarged view of the pump head.
[0027] Figure 3 yes Figure 1 A partial enlarged view of the motor part.
[0028] Figure numerals: 1. pump jacket; 2. O-ring seal; 3. suction end cover; 4. middle section casing; 5. guide vane; 6. impeller; 7. balance ring; 8. wear-resistant ring; 9. balance ring seat; 10. pump body; 11. connecting section; 12. connecting section circulation hole; 13. auxiliary impeller; 14. motor housing front flange; 15. motor housing front flange circulation hole; 16. outer shell; 17. inner shell; 18. outlet; 19. motor housing rear flange; 20. motor housing rear cover; 21. rear bearing body; 22. terminal box seat; 23. shaft; 24. rotor; 25. stator; 26. rotor shielding sleeve; 27. rotor shielding plate; 28. reinforcement sleeve; 29. stator shielding sleeve; 30. auxiliary wear-resistant ring; 31. sliding bearing; 32. rear bearing body circulation hole. DETAILED DESCRIPTION
[0029] The present invention is further described below with reference to the embodiments:
[0030] Example 1
[0031] This embodiment discloses a high-pressure, low-temperature, vertical multi-stage canned motor pump that uses a medium as motor jacket cooling water. Figure 1 , Figure 2 , Figure 3 As shown, the high-pressure and low-temperature vertical multi-stage canned motor pump using a medium as motor jacket cooling water comprises: a pump head unit, a canned motor unit, and a shaft 23 passing through the pump head unit and the canned motor unit.
[0032] The pump head unit comprises: a pump jacket 1, a suction end cover 3, a multi-stage impeller mechanism, a plurality of middle section shells 4 fixedly connected in sequence, an axial force balancing mechanism, a pump body 10, an auxiliary impeller mechanism and a connecting section 11; the suction end cover 3 is fixedly connected to the first pump middle section shell 4, the last pump middle section shell 4) is connected to the pump body 10, the side of the pump body 10 facing away from the middle section shell 4 is connected to the connecting section 11, each pump middle section shell 4 is correspondingly arranged outside the impeller mechanism, the pump body 10 is arranged outside the axial force balancing mechanism, and the connecting section 11 is arranged outside the auxiliary impeller mechanism; the impeller mechanism comprises an impeller 6 and a guide vane 5 arranged on the impeller 6; the axial force balancing mechanism includes a wear-resistant ring 8 installed on the last-stage impeller 6, a balance ring seat 9 installed on the connecting section 11 and a balance ring 7 installed on the balance ring seat 9, and cooperates with the circulation hole of the shaft 23 on the impeller side to complete the balance of the axial force. When the pump is running, the wear-resistant ring 8 rotates with the last-stage impeller 6, and the balance ring 7 is fixed; the auxiliary impeller mechanism includes an auxiliary impeller 13 and an auxiliary wear-resistant ring 30 installed on the front flange 14 of the motor housing, which is used to increase the medium pressure inside the rotor cavity; the impeller mechanism and the auxiliary impeller mechanism are both installed on the shaft 23.
[0033] The shielded motor unit comprises: a stator assembly and a rotor 24; the stator assembly comprises a motor housing assembly, a stator 25 and a motor housing rear cover 20; the motor housing assembly comprises an outlet 18, an inner shell 17, an outer shell 16, a motor housing front flange 14, a motor housing rear flange 19 and a terminal box seat 22, and the six parts are integrated into one by welding. During the operation of the pump, the inner and outer shells are filled with a medium for cooling the motor, the inner shell 17 is subjected to external pressure, and the outer shell 16 is subjected to internal pressure; the stator 25 is arranged inside the inner shell 17, and the stator 25 can play an auxiliary pressure-bearing role for the inner shell 17, and the motor housing rear cover 20 is connected to the motor housing rear flange 19 to close the motor cavity; a stator shielding sleeve 29 is embedded inside the stator assembly, and the stator shielding sleeve 29 is welded to the motor housing front flange 14 and the motor housing rear cover 20 respectively to ensure that the shielded motor stator assembly is isolated from the conveying medium. The outer circumference of the rotor 24 is inlaid with a rotor shielding sleeve 26, and both ends of the rotor 24 are inlaid with rotor shielding plates 27 respectively. The rotor shielding sleeve 26 is welded to the rotor shielding plate 27, and the rotor shielding plate 27 is welded to the shaft 23 to ensure that the rotor 24 is isolated from the conveying medium.
[0034] The shaft 23 has circulation holes on one side of the impeller 6 in the axial direction and in the radial direction, respectively, to cooperate with the axial force balancing mechanism to balance the axial force.
[0035] The motor cooling chamber is located between the inner shell 17 and the outer shell 16 of the motor housing. The motor housing front flange 14 is provided with a motor housing front flange circulation hole 15 connecting the pump body 10 outlet and the motor cooling chamber. The end of the motor cooling chamber away from the pump body 10 outlet is connected to the outlet 18.
[0036] A shielded motor cooling gap is provided between the stator shielding sleeve 29 and the rotor shielding sleeve 26, a connecting section circulation hole 12 is provided on the connecting section 11 to connect the pump body 10 outlet and the chamber where the auxiliary impeller 13 is located, the chamber where the auxiliary impeller 13 is located is connected to the shielded motor cooling gap, and a rear bearing body circulation hole 32 is provided on the rear bearing body 21 to connect the shielded motor cooling gap and the outlet 18. The size of the circulation hole is determined comprehensively according to factors such as the shielded motor circulation amount, the motor temperature rise, and the medium vaporization pressure curve;
[0037] A stopper and an O-ring seal 2 are provided between the suction end cover 3 and the pump jacket 1;
[0038] A thickened reinforcement sleeve 28 is installed outside the stator shield sleeve 29, and the thickness of the reinforcement sleeve 28 is determined according to the pressure in the rotor cavity;
[0039] The outer shell 16 is provided with an outlet 18;
[0040] The upper end of the motor housing rear flange 19 is connected to the terminal box seat 22 through a section of steel pipe. After the entire motor housing is roughly machined, this section of steel pipe is welded, and then the stator is hot-mounted, and then the motor housing assembly is finely machined, and finally the terminal box seat 22 is welded on this section of steel pipe.
[0041] In this embodiment, the impeller 6, the shaft 23, the rotor 24, a pair of sliding bearings 31, the wear-resistant ring 8, the auxiliary impeller 13 and the like constitute the rotating parts of the pump. The pump jacket 1 of the pump head unit is filled with the conveying medium, the inner and outer shells of the motor housing of the shielded motor unit are filled with the conveying medium, the rotor cavity of the shielded motor unit is filled with the conveying medium, the stator assembly of the shielded motor is isolated from the conveying medium by the stator shielding sleeve 29, the rotor 24 is isolated from the conveying medium by the rotor shielding sleeve 26 and the rotor shielding plate 27, and the inside of the stator shielding sleeve 29 is filled with the conveying medium.
[0042] The specific working process of the utility model is as follows: the rotating parts of the multi-stage shielded pump are supported by a pair of sliding bearings 31 and rotate in the conveying medium. Most of the conveying medium is pressurized step by step through the multi-stage impeller mechanism of the pump head unit and discharged from the pump body 10 outlet. A stopper is provided between the suction end cover 3 and the pump jacket 1 to cooperate with an O-ring seal to prevent the high-pressure medium from flowing back to the inlet and affecting the circulation of the medium. Most of the medium flows through the motor housing front flange circulation hole 15 in the motor housing front flange 14 to the motor cooling cavity between the inner shell 17 and the outer shell 16 of the motor housing to cool the motor and flows out from the outlet 18; a part of the medium discharged from the pump body 10 outlet also flows to the auxiliary impeller 13 through the connecting section circulation hole 12 in the connecting section 11, and then flows into the rotor cavity under pressure through the auxiliary impeller 13, and then cools the shielded motor through the gap between the stator shielding sleeve 29 and the rotor shielding sleeve 26, and then flows to the outlet 18 through the circulation hole 32 on the rear bearing body 21, and completes automatic exhaust at the same time, and is discharged from the exhaust valve at the highest point of the whole pump. According to the working condition requirements, the flow head is relatively large, the medium viscosity is particularly small, the medium temperature is extremely low, the medium vaporization pressure is particularly high, and the medium vaporization pressure curve is particularly affected by temperature changes. In addition, since the medium temperature is extremely low, the cooling water will freeze if the motor jacket directly passes through the cooling water. In addition, since the vaporization pressure of the medium is relatively high, the shielded pump itself requires a high-pressure design. Based on the existing hydraulics and motors, the utility model makes the pump perfectly adapt to the working conditions of the medium through structural adjustment, theoretical calculation, and motor heat balance calculation, and the pump runs stably.
[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.
Claims
1. A high-pressure, low-temperature, vertical multi-stage canned motor pump that uses a medium as motor jacket cooling water, characterized in that: include: A pump head unit, a shielded motor unit, and a shaft (23) passing through the pump head unit and the shielded motor unit; The pump head unit comprises: a pump jacket (1), a suction end cover (3), a multi-stage impeller mechanism, a plurality of middle section casings (4) fixedly connected in sequence, an axial force balancing mechanism, a pump body (10), an auxiliary impeller mechanism and a connecting section (11); the suction end cover (3) is fixedly connected to the first pump middle section casing (4), the last pump middle section casing (4) is connected to the pump body (10), the side of the pump body (10) facing away from the middle section casing (4) is connected to the connecting section (11), each pump middle section casing (4) is correspondingly arranged outside the impeller mechanism, the pump body (10) is arranged outside the axial force balancing mechanism, and the connecting section (11) is arranged outside the auxiliary impeller mechanism; the impeller mechanism and the auxiliary impeller mechanism are both mounted on the shaft (23); The shielded motor unit comprises: a stator assembly and a rotor (24); the stator assembly comprises a motor housing assembly, a stator (25) and a motor housing rear cover (20); the motor housing assembly comprises an outlet (18), an inner shell (17), an outer shell (16), a motor housing front flange (14), a motor housing rear flange (19) and a terminal box seat (22); the outer shell (16) is provided with the outlet (18), the stator (25) is arranged inside the inner shell (17), the motor housing rear cover (20) is connected to the motor housing rear flange The stator assembly is connected with a flange (19); a stator shielding sleeve (29) is embedded in the stator assembly, and the stator shielding sleeve (29) is respectively welded to the front flange (14) of the motor housing and the rear cover (20) of the motor housing; a rotor shielding sleeve (26) is embedded in the outer circumference of the rotor (24), and rotor shielding plates (27) are respectively embedded at both ends of the rotor (24), the rotor shielding sleeve (26) is welded to the rotor shielding plate (27), and the rotor shielding plate (27) is welded to the shaft (23); a rear bearing body (21) is installed on the rear cover (20) of the motor housing; A motor cooling chamber is provided between the inner shell (17) and the outer shell (16) of the motor housing. A motor housing front flange circulation hole (15) is provided on the front flange (14) of the motor housing for connecting the pump body (10) outlet and the motor cooling chamber. The end of the motor cooling chamber away from the pump body (10) outlet is connected to the outlet (18). A shielded motor cooling gap is provided between the stator shielding sleeve (29) and the rotor shielding sleeve (26). A connecting section circulation hole (12) is provided on the connecting section (11) for connecting the pump body (10) outlet and the chamber where the auxiliary impeller mechanism is located. The chamber where the auxiliary impeller mechanism is located is connected to the shielded motor cooling gap. A rear bearing body circulation hole (32) is provided on the rear bearing body (21) for connecting the shielded motor cooling gap and the outlet (18).
2. According to claim 1, the high-pressure, low-temperature vertical multi-stage canned motor pump using a medium as the motor jacket cooling water is characterized in that: The shaft (23) is provided with an axial force balancing circulation hole on one side of the impeller (6).
3. According to claim 1, the high-pressure, low-temperature vertical multi-stage canned motor pump using a medium as cooling water for the motor jacket is characterized in that: The auxiliary impeller mechanism comprises an auxiliary impeller (13) and an auxiliary wear-resistant ring (30) mounted on a front flange (14) of a motor housing.
4. According to claim 1, the high-pressure, low-temperature vertical multi-stage canned motor pump using a medium as the motor jacket cooling water is characterized in that: A stopper and O-ring seal (2) are provided between the suction end cover (3) and the pump jacket (1).
5. According to claim 1, the high-pressure, low-temperature vertical multi-stage canned motor pump using a medium as the motor jacket cooling water is characterized in that: The impeller mechanism comprises an impeller (6) and guide vanes (5) arranged on the impeller (6).
6. The high-pressure, low-temperature vertical multi-stage canned motor pump using a medium as cooling water for the motor jacket according to claim 5, characterized in that: The axial force balancing mechanism comprises a wear-resistant ring (8) mounted on the last-stage impeller (6), a balancing ring seat (9) mounted on the connecting section (11), and a balancing ring (7) mounted on the balancing ring seat (9).
7. The high-pressure, low-temperature vertical multi-stage canned motor pump using a medium as cooling water for the motor jacket according to claim 1, characterized in that: A reinforcement sleeve (28) is installed outside the stator shielding sleeve (29).
8. The high-pressure, low-temperature vertical multi-stage canned motor pump using a medium as cooling water for the motor jacket according to claim 7, characterized in that: A sliding bearing (31) is installed on the connecting section (11); and a sliding bearing (31) is installed on the rear bearing body (21).
9. The high-pressure, low-temperature vertical multi-stage canned motor pump using a medium as motor jacket cooling water according to claim 1, characterized in that: The outlet (18), the inner shell (17), the outer shell (16), the motor housing front flange (14), the motor housing rear flange (19) and the terminal box seat (22) are integrated into one by welding.