CN219388179U

CN219388179U - Large-scale high-pressure submersible sewage pump

Info

Publication number: CN219388179U
Application number: CN202223248988.2U
Authority: CN
Inventors: 周跃; 张培富; 王娇; 张锡淼
Original assignee: Shanghai Liancheng Group Co Ltd
Current assignee: Shanghai Liancheng Group Co Ltd
Priority date: 2022-12-05
Filing date: 2022-12-05
Publication date: 2023-07-21
Anticipated expiration: 2032-12-05

Abstract

The utility model relates to a large-scale high-pressure submersible sewage pump which comprises a pump and a high-pressure submersible motor which are connected with each other, wherein the high-pressure submersible motor comprises a rotor, and the pump comprises a third bearing, a pump cover, a pump body and a bearing seat; the third bearing is a thrust self-aligning roller bearing; the third bearing and the bearing seat are both sleeved at the lower end of the rotor, the third bearing is fixed in a cavity of the bearing seat, a retainer ring is arranged above the third bearing, the bearing seat is fixed on the pump cover, and the pump cover is fixed on the pump body. Compared with the prior art, the utility model has the advantages of reasonable structure, strong bearing capacity, high reliability and the like.

Description

Large-scale high-pressure submersible sewage pump

Technical Field

The utility model relates to the field of sewage pump equipment, in particular to a submersible sewage pump.

Background

The submersible sewage pump is a pump product which is a pump and motor integrated coaxial device and simultaneously works under the submerged. The submersible sewage pump can discharge substances such as particles, fibers and the like in sewage along with liquid. The submersible sewage pump has the advantages of strong drainage and sewage discharge capability, flexible installation mode, low civil engineering cost and the like, and more occasions select the submersible sewage pump.

The drainage or waterlogging engineering conditions tend to be high flow and low lift, resulting in a need for a higher power sewage pump. When the flow is large, the pump matching power is large, and is generally larger than a 355kW water pump, namely a matching high-voltage motor. Under the working condition, according to the past experience, the average flow of a plurality of pumps is taken, the power of a single pump is not so high, and the low-voltage submersible motor can be matched. The pumps are corresponding to a plurality of rotary machines and pipeline inputs, corresponding to a plurality of civil engineering costs and corresponding to a plurality of management costs. There is a need for a large submersible sewage pump with a high-pressure submersible motor to save various capital investment.

Disclosure of Invention

The utility model aims at providing a large-sized high-pressure submersible sewage pump which can be suitable for a large sewage treatment pump station or a temporary water taking pump station. The proposal solves the fixed thinking that the large-sized high-pressure submersible sewage pump has high manufacturing starting point, high manufacturing difficulty, poor reliability, high operation and maintenance cost, no development and application are necessary and the like in the impression of people.

The aim of the utility model can be achieved by the following technical scheme:

the large-scale high-pressure submersible sewage pump comprises a pump and a high-pressure submersible motor which are connected with each other, wherein the high-pressure submersible motor comprises a rotor, and the pump comprises a third bearing, a pump cover, a pump body and a bearing seat; the third bearing is a thrust self-aligning roller bearing;

the third bearing and the bearing seat are both sleeved at the lower end of the rotor, the third bearing is fixed in a cavity of the bearing seat, a retainer ring is arranged above the third bearing, the bearing seat is fixed on the pump cover, and the pump cover is fixed on the pump body.

Preferably, the connecting seat, the bearing seat and the pump cover form a first oil chamber, the bearing seat, the machine seal seat and the rotor form a second oil chamber, one side of the bearing seat is provided with an oil hole, and the oil hole is communicated with the first oil chamber and the second oil chamber.

Preferably, the pump further comprises a machine seal seat, wherein machine seal cavities are arranged at two ends of the interior of the machine seal seat, and the machine seal seat is fixed below the bearing seat;

the connecting seat is provided with a first mechanical seal at the joint of the connecting seat and the rotor, a second mechanical seal is arranged at the joint of the mechanical seal seat, the second oil chamber and the rotor, and a third mechanical seal is arranged between the lower end of the mechanical seal seat and the rotor.

Preferably, the first mechanical seal is an M37G mechanical seal, the second mechanical seal is an M37G mechanical seal, and the third mechanical seal is a 227-HGH mechanical seal.

Preferably, a threaded hole is formed in one side of the machine seal seat, the threaded hole is communicated with the second oil chamber, and a screw plug is arranged in the threaded hole.

Preferably, the submersible sewage pump further comprises a protection component, wherein the protection component is connected with an electric control cabinet and comprises an oil-water probe, a platinum thermal resistor, a vibration transmitter, a heating belt and a humidity sensor;

the oil-water probe is fixed in a first oil chamber and a wiring cavity below the connecting seat, the wiring cavity is formed by an upper motor end cover and a wiring box cover, one end of the upper motor end cover is connected with the stator, and the other end of the upper motor end cover is connected with the wiring box cover; the platinum thermal resistor is fixed on the outer rings of the first bearing and the second bearing and in the windings of the stator; the vibration transmitter is fixed on a first bearing cover and a second bearing cover of the high-voltage submersible motor; the heating belt is fixed on the stator winding of the high-voltage submersible motor; the humidity sensor is positioned in a wiring cavity of the high-voltage submersible motor.

Preferably, the high-voltage submersible motor further comprises a first bearing, a first bearing gland, a stator, a second bearing gland, a second bearing, a connecting seat and a lifting frame, wherein the first bearing and the second bearing are respectively a cylindrical roller bearing and a deep groove ball bearing;

the first bearing and the first bearing gland are both sleeved at the upper end of the rotor, the first bearing gland is located below the first bearing, the second bearing cover and the connecting seat are both sleeved at the middle lower part of the rotor, the second bearing cover is located above the second bearing, the second bearing is fixed in a bearing cavity on the connecting seat, the pump cover is arranged at the upper end of the pump, one end of the connecting seat is connected with the high-voltage submersible motor, the other end of the connecting seat is connected with the pump, and two ends of the lifting frame are fixed at two sides of the upper end cover of the motor.

Preferably, the pump comprises an impeller and a sealing ring, wherein the impeller is provided with a balance hole structure, the impeller is fixed at the lower end of the rotor, the impeller is provided with a rear opening ring, and a gap is reserved between the rear opening ring and the sealing ring.

Preferably, the sealing ring comprises a first sealing ring and a second sealing ring, the first sealing ring is arranged in the pump cover, and the second sealing ring is positioned in the pump body.

Preferably, the impeller is fixed on the rotor through a first nut and a second nut, a countersunk screw hole is formed in the first nut, the first nut is fixed on the impeller through a screw, and the second nut is fixed on the outer side of the first nut.

Compared with the prior art, the utility model has the following advantages:

(1) Considering that the large pump rotor is longer, the scheme sets up the third bearing below the second bearing on the basis of two bearing supports in the field of rotary machinery, and the third bearing selects a thrust self-aligning roller bearing, and the bearing has better axial load capacity and self-aligning capacity, and the slope of the adjustable rotor shaft, through the setting of the third bearing, each bearing capacity has been greatly optimized. Meanwhile, the fact that the vibration to which the first bearing is subjected is the largest due to the fact that the rotor is longer is considered, the first bearing is a cylindrical roller bearing which is more resistant to radial force, the second bearing is still mainly subjected to radial force, and therefore the second bearing is a deep groove ball bearing. The bearing capacity of each bearing is optimized through the selection of the bearing and the addition of the third bearing, so that the reliability of the device is further improved.

(2) In the scheme, the upper end and the lower end of the inner sides of the first oil chamber and the second oil chamber are sealed through the first mechanical seal and the second mechanical seal, so that the tightness and the safety of the oil chamber are ensured; meanwhile, a third mechanical seal is added on one side of the oil chamber close to the impeller, so that the tightness of the oil chamber is further ensured. Meanwhile, the third mechanical seal is a 227-HGH mechanical seal, the sealing material is silicon carbide or tungsten carbide, the sealed mechanical spring is not contacted with a medium, the sealing failure caused by the fact that small particles are blocked by the spring in the pollution discharge process is effectively prevented, and the sealing reliability of the device is improved.

(3) According to the scheme, the impeller is reliably mounted at the lower end of the rotor through the double-nut structure formed by the first nut and the second nut, the double-nut effectively plays a role in looseness prevention, the countersunk screw hole is formed in the first nut, and the first nut is fixedly connected with the impeller by the aid of the combined screw to strengthen looseness prevention. When water is stopped, water flows back into the flow channel, the impeller can rotate reversely, so that the nuts are loosened, the risk of loosening and falling off of the first nut and the second nut under the condition is effectively avoided, and the safety and reliability of the device are improved.

(4) According to the scheme, through reasonable configuration of a plurality of protection components, monitoring and protection of the sewage pump are realized, and nearby water leakage conditions are detected by an oil-water probe of a first oil chamber and a wiring chamber; if the platinum thermal resistor is arranged on the periphery of the first bearing and the second bearing, the temperature of the bearing is monitored in real time; if the stator winding is provided with a platinum thermal resistor, the temperature rise of the stator winding is monitored in real time; if vibration sensors are arranged on the periphery of the first bearing and the periphery of the second bearing, the vibration amplitude of the bearings is effectively monitored; if the stator winding is provided with a heating belt, the problem of condensation before starting up is solved.

Drawings

FIG. 1 is a schematic diagram of a large-scale high-pressure submersible sewage pump provided by the utility model;

FIG. 2 is a schematic diagram of the connection between the high-voltage submersible motor and the pump structure;

FIG. 3 is an enlarged schematic view of the structure of FIG. 2A;

FIG. 4 is an enlarged schematic view of the structure of FIG. 2B;

FIG. 5 is an enlarged schematic view of the structure of FIG. 2C;

FIG. 6 is a cross-sectional view of a front view of the seal carrier provided by the present utility model;

FIG. 7 is a left side view of the seal holder of the present utility model;

FIG. 8 is a cross-sectional view of a front view of a bearing housing provided by the present utility model;

in the figure: 1. the lifting frame comprises a lifting frame body, 2, a junction box cover, 3, a motor upper end cover, 4, a first bearing, 5, a first bearing gland, 6, a stator, 7, a rotor, 8, a second bearing gland, 9, a second bearing, 10, a first mechanical seal, 11, a third bearing, 12, a second mechanical seal, 13, a third mechanical seal, 14, a first sealing ring, 15, a second sealing ring, 16, a screw, 17, a second nut, 18, a first nut, 19, an impeller, 20, a pump body, 21, a screw plug, 22, a mechanical seal seat, 23, a pump cover, 24, a bearing seat, 25, a retainer ring, 26, a connecting seat, 27, a second oil chamber, 28, an oil hole, 29, a threaded hole, 30 and a first oil chamber.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. The components of the embodiments of the present utility model generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the utility model, as presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

In the description of the present utility model, it should be noted that, directions or positional relationships indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., are directions or positional relationships based on those shown in the drawings, or are directions or positional relationships conventionally put in use of the inventive product, are merely for convenience of describing the present utility model and simplifying the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific direction, be constructed and operated in a specific direction, and thus should not be construed as limiting the present utility model.

It should be noted that the terms "first," "second," and "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implying a number of technical features being indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

Furthermore, the terms "horizontal," "vertical," and the like do not denote a requirement that the component be absolutely horizontal or overhang, but rather may be slightly inclined. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

Example 1

As shown in fig. 1 to 8, a large-sized high-pressure submersible sewage pump comprises a pump and a high-pressure submersible motor which are connected with each other, wherein the high-pressure submersible motor comprises a rotor 7, and the pump comprises a third bearing 11, a pump cover 23, a pump body 20 and a bearing seat 24; the third bearing 11 is a thrust self-aligning roller bearing;

the third bearing 11 and the bearing seat 24 are both sleeved at the lower end of the rotor 7, the third bearing 11 is fixed in a cavity of the bearing seat 24, a retainer ring 25 is arranged above the third bearing 11, the bearing seat 24 is fixed on a pump cover 23, and the pump cover 23 is fixed on the pump body 20.

Bearing load description: the first bearing 4 and the second bearing 9 respectively adopt a cylindrical roller bearing radial bearing and a deep groove ball bearing radial bearing to bear radial load, and the third bearing 11 adopts an axial bearing thrust aligning roller bearing to bear axial force.

According to the scheme, on the basis of supporting of the existing two bearings, the third bearing 11 is arranged at the connection position of the high-pressure submersible motor and the pump, the third bearing 11 is a thrust self-aligning roller bearing, the bearing has good axial load capacity and self-aligning capacity, the inclination of the rotor shaft can be adjusted, and the bearing capacity of each bearing is greatly optimized through the arrangement of the third bearing 11. Meanwhile, considering that the rotor 7 is longer and the vibration to which the first bearing 4 is subjected is the greatest, the first bearing 4 is a cylindrical roller bearing which is more resistant to radial force, the second bearing 9 is still mainly subjected to radial force, and the second bearing 9 is a deep groove ball bearing. The reliability of the device is further improved by optimizing the bearing capacity of each bearing through the selection of the bearing and the addition of the third bearing 11.

As a preferred embodiment, as shown in fig. 5 to 8, the connecting seat 26, the bearing seat 24 and the pump cover 23 form a first oil chamber 30, the bearing seat 24, the seal seat 22 and the rotor 7 form a second oil chamber 27, an oil hole 28 is provided at one side of the bearing seat 24, and the oil hole 28 communicates the first oil chamber 30 and the second oil chamber 27.

The pump also comprises a machine seal seat 22, wherein machine seal cavities are arranged at two ends of the interior of the machine seal seat 22, and the machine seal seat 22 is fixed below the bearing seat 24;

the joint of the connecting seat 26 and the rotor 7 is provided with a first mechanical seal 10, the joint of the mechanical seal seat 22, the second oil chamber 27 and the rotor 7 is provided with a second mechanical seal 12, and a third mechanical seal 13 is arranged between the lower end of the mechanical seal seat 22 and the rotor 7.

The first mechanical seal 10 is an M37G mechanical seal, the second mechanical seal 12 is an M37G mechanical seal, and the third mechanical seal 13 is a 227-HGH mechanical seal.

In the scheme, the upper and lower ends of the inner sides of the first oil chamber 30 and the second oil chamber 27 are sealed through the first mechanical seal 10 and the second mechanical seal 12, so that the tightness and the safety of the oil chambers are ensured; meanwhile, a third mechanical seal 13 is added on one side of the oil chamber close to the impeller 19, so that the tightness of the oil chamber is further ensured. Meanwhile, the third mechanical seal 13 is a 227-HGH mechanical seal, the sealing material is silicon carbide or tungsten carbide, and the sealed mechanical spring is not contacted with a medium, so that the sealing failure caused by small particles jamming the spring in the pollution discharge process is effectively prevented, and the sealing reliability of the device is improved.

As shown in fig. 3-7, a threaded hole 29 is formed in one side of the machine seal seat 22, the threaded hole 29 is communicated with the second oil chamber 27, and a screw plug 21 is arranged in the threaded hole 29.

In the scheme, the threaded hole 29 is formed in one side of the mechanical seal seat 22 and is used for communicating the oil chamber with the external environment, after the third mechanical seal 13 is installed, the second oil chamber is subjected to an airtight test through the threaded hole 29 before oiling, and the tightness of the third mechanical seal 13 is checked. After the air tightness test is completed, the screw hole 29 is sealed by the screw plug 21.

The submersible sewage pump also comprises a protection component, wherein the protection component is connected with an electric control cabinet and comprises an oil-water probe, a platinum thermal resistor, a vibration transmitter, a heating belt and a humidity sensor;

the oil-water probe is fixed in a first oil chamber 30 and a wiring cavity under the connecting seat 26, the wiring cavity is formed by an upper motor end cover 3 and a wiring box cover 2, one end of the upper motor end cover 3 is connected with a stator 6, and the other end is connected with the wiring box cover 2; the platinum thermal resistor is fixed on the outer rings of the first bearing 4 and the second bearing 9 and in the windings of the stator 6; the vibration transmitter is fixed on a first bearing cover 5 and a second bearing cover 8 of the high-voltage submersible motor; the heating belt is fixed on the winding of the stator 6 of the high-voltage submersible motor; the humidity sensor is positioned in the wiring cavity of the high-voltage submersible motor.

The protection of the high-voltage submersible motor is realized through the protection components such as the oil-water probe, the platinum thermal resistor, the vibration transmitter, the heating belt, the humidity sensor and the like which are arranged in the electric control cabinet and the pump. When the motor leaks water, the temperature of the bearing is too high or the temperature of the winding of the stator 6 is too high, the electric control cabinet is powered off to protect the motor; when the vibration of the bearing exceeds the standard or the humidity of the wiring cavity of the high-voltage submersible motor exceeds the standard, the electric control cabinet can generate an alarm action; before each pump operation, the electric control cabinet can control the heating belt to heat, so that condensation on the stator is evaporated, the condensation is prevented from reducing the insulating property of the motor, and the normal operation of the device is influenced. According to the scheme, a plurality of protection measures are carried out on the device, so that the running safety and reliability of the submersible sewage pump are further improved.

The high-voltage submersible motor further comprises a first bearing 4, a first bearing gland 5, a stator 6, a second bearing gland 8, a second bearing 9, a connecting seat 26 and a lifting frame 1, wherein the first bearing 4 and the second bearing 9 are respectively a cylindrical roller bearing and a deep groove ball bearing;

the first bearing 4 and the first bearing gland 5 are all sleeved at the upper end of the rotor 7, the first bearing gland 5 is located below the first bearing, the second bearing 9, the second bearing cover 8 and the connecting seat 26 are all sleeved at the middle lower part of the rotor 7, the second bearing cover 8 is located above the second bearing 9, the second bearing 9 is fixed in a bearing cavity on the connecting seat 26, the pump upper end is provided with a pump cover 23, one end of the connecting seat 26 is connected with the high-voltage submersible motor, the other end is connected with the pump, and two ends of the lifting frame 1 are fixed at two sides of the motor upper end cover 3.

The pump also comprises an impeller 19 and a sealing ring, wherein the impeller 19 is provided with a balance hole structure, the impeller 19 is fixed at the lower end of the rotor 7, the impeller 19 is provided with a rear opening ring, and a gap is reserved between the rear opening ring and the sealing ring.

In the scheme, the impeller 19 is provided with the balance hole structure so as to effectively balance the axial force, and in the embodiment, the impeller 19 can balance about 85% of the axial force through the arrangement of the balance hole structure; meanwhile, high-pressure fluid at the outlet of the impeller 19 leaks through a rear port ring at the upper end of the impeller 19 and flows back to the balance hole, the balance hole is positioned in a low-pressure area, and the front low-pressure area and the rear low-pressure area of the impeller are communicated to play a role in balancing axial force; on the other hand, the gap formed between the rear opening ring and the first sealing ring is smaller, so that large-particle media can be effectively isolated.

The sealing rings include a first sealing ring 14 and a second sealing ring 15, the first sealing ring 14 being disposed within the pump cover 23, the second sealing ring 15 being located within the pump body 20.

As shown in fig. 2 to 4, the impeller 19 is fixed to the rotor 7 by a first nut 18 and a second nut 17, a countersunk screw hole is provided in the first nut 18, the first nut 18 is fixed to the impeller 19 by a screw 16, and the second nut 17 is fixed to the outside of the first nut 18.

According to the scheme, the impeller 19 is reliably mounted at the lower end of the rotor 7 through the double-nut structure formed by the first nut 18 and the second nut 17, the double-nut is used for preventing loosening, the countersunk screw holes are formed in the first nut 18, the first nut 18 and the impeller 19 are fixedly connected through the combined screw 16, and the anti-loosening effect is achieved again. When water is stopped, water flows back into the flow channel, and the impeller 19 can rotate reversely. The nut is easy to loosen and fall off under the reverse rotation, the application of the double nuts avoids the risk of loosening and falling off of the first nut 18 and the second nut 17, and the safety and the reliability of the device are improved.

The foregoing describes in detail preferred embodiments of the present utility model. It should be understood that numerous modifications and variations can be made in accordance with the concepts of the utility model by one of ordinary skill in the art without undue burden. Therefore, all technical solutions which can be obtained by logic analysis, reasoning or limited experiments based on the prior art by the person skilled in the art according to the inventive concept shall be within the scope of protection defined by the claims.

Claims

1. The large-scale high-pressure submersible sewage pump comprises a pump and a high-pressure submersible motor which are connected with each other, wherein the pump and the high-pressure submersible motor are connected through a connecting seat (26), and the large-scale high-pressure submersible sewage pump is characterized in that the high-pressure submersible motor comprises a rotor (7), and the pump comprises a third bearing (11), a pump cover (23), a pump body (20) and a bearing seat (24); the third bearing (11) is a thrust self-aligning roller bearing;

the third bearing (11) and the bearing seat (24) are sleeved at the lower end of the rotor (7), the third bearing (11) is fixed in a cavity of the bearing seat (24), a retainer ring (25) is arranged above the third bearing (11), the bearing seat (24) is fixed on a pump cover (23), and the pump cover (23) is fixed on the pump body (20);

the connecting seat (26), the bearing seat (24) and the pump cover (23) form a first oil chamber (30), the bearing seat (24), the machine seal seat (22) and the rotor (7) form a second oil chamber (27), one side of the bearing seat (24) is provided with an oil hole (28), and the oil hole (28) is communicated with the first oil chamber (30) and the second oil chamber (27);

the pump comprises an impeller (19) and a sealing ring, wherein the impeller (19) is provided with a balance hole structure, the impeller (19) is fixed at the lower end of the rotor (7), the impeller (19) is provided with a rear mouth ring, and a gap is reserved between the rear mouth ring and the sealing ring.

2. The large-scale high-pressure submersible sewage pump according to claim 1, wherein the pump further comprises a machine seal seat (22), machine seal cavities are arranged at two ends inside the machine seal seat (22), and the machine seal seat (22) is fixed below a bearing seat (24);

the connecting seat (26) is provided with a first mechanical seal (10) at the joint of the rotor (7), a second mechanical seal (12) is provided at the joint of the mechanical seal seat (22), the second oil chamber (27) and the rotor (7), and a third mechanical seal (13) is provided between the lower end of the mechanical seal seat (22) and the rotor (7).

3. A large high pressure submersible sewage pump according to claim 2, characterized in that the first mechanical seal (10) is an M37G mechanical seal, the second mechanical seal (12) is an M37G mechanical seal, and the third mechanical seal (13) is a 227-HGH mechanical seal.

4. A large-scale high-pressure submersible sewage pump according to claim 3, characterized in that a threaded hole (29) is provided on one side of the machine seal seat (22), the threaded hole (29) is communicated with a second oil chamber (27), and a screw plug (21) is provided in the threaded hole (29).

5. The large-scale high-pressure submersible sewage pump according to claim 1, further comprising a protection component, wherein the protection component is connected with an electric cabinet and comprises an oil-water probe, a platinum thermal resistor, a vibration transmitter, a heating belt and a humidity sensor;

the oil-water probe is fixed in a first oil chamber (30) and a wiring cavity below the connecting seat (26), the wiring cavity is formed by an upper motor end cover (3) and a wiring box cover (2), one end of the upper motor end cover (3) is connected with a stator (6), and the other end of the upper motor end cover is connected with the wiring box cover (2); the platinum thermal resistor is fixed on the outer rings of the first bearing (4) and the second bearing (9) and in the windings of the stator (6); the vibration transmitter is fixed on a first bearing gland (5) and a second bearing gland (8) of the high-pressure submersible motor; the heating belt is fixed on a winding of a stator (6) of the high-voltage submersible motor; the humidity sensor is positioned in a wiring cavity of the high-voltage submersible motor.

6. A large high pressure submersible sewage pump according to claim 5, characterized in that the high pressure submersible motor further comprises a first bearing (4), a first bearing gland (5), a stator (6), a second bearing gland (8), a second bearing (9), a connection seat (26) and a lifting frame (1), the first bearing (4) and the second bearing (9) being respectively a cylindrical roller bearing and a deep groove ball bearing;

the novel submersible motor is characterized in that the first bearing (4) and the first bearing gland (5) are sleeved at the upper end of the rotor (7), the first bearing gland (5) is located below the first bearing, the second bearing (9), the second bearing gland (8) and the connecting seat (26) are sleeved at the middle lower part of the rotor (7), the second bearing gland (8) is located above the second bearing (9), the second bearing (9) is fixed in a bearing cavity on the connecting seat (26), the pump cover (23) is arranged at the upper end of the pump, one end of the connecting seat (26) is connected with the high-pressure submersible motor, the other end of the connecting seat is connected with the pump, and two ends of the lifting frame (1) are fixed at two sides of the upper end cover (3) of the motor.

7. A large high pressure submersible sewage pump according to claim 1, characterized in that the sealing rings comprise a first sealing ring (14) and a second sealing ring (15), the first sealing ring (14) being arranged in the pump cover (23), the second sealing ring (15) being located in the pump body (20).

8. A large high pressure submersible sewage pump according to claim 1, characterized in that the impeller (19) is fixed on the rotor (7) by means of a first nut (18) and a second nut (17), a countersunk screw hole is provided in the first nut (18), the first nut (18) is fixed on the impeller (19) by means of a screw (16), and the second nut (17) is fixed on the outside of the first nut (18).