Impeller assembly for a multi-stage submersible pump

Abstract

The present invention discloses an impeller assembly for a multi-stage submersible pump, including an impeller shell, wherein the impeller shell is provided with: an impeller, a guide vane and a mouth ring, the impeller is sleeved on the pump shaft and can slide along the axial direction of the pump shaft, and a liquid inlet is provided at the lower end thereof, and the fluid medium enters the impeller through the liquid inlet; the guide vane is arranged above the impeller, and is inserted and fixed with the impeller shell, and a liquid outlet cavity connected with a liquid flow channel is formed between the impeller and the impeller shell; the top surface of the impeller shell is provided with a liquid outlet, which is connected with the liquid outlet cavity; the guide vane is floatingly sleeved on the pump shaft; the mouth ring is movably arranged between the outer side surface of the liquid inlet portion and the inner side surface of the impeller shell through a mouth ring seat. In the present invention, the guide vane floatingly arranged on the pump shaft bears the axial force generated by the rotation of the impeller, thereby improving the balancing effect of the impeller axial force; the mouth ring is movably arranged through the mouth ring seat, thereby avoiding the wear between the mouth ring and the impeller and the pump shell, which causes the mouth ring gap to increase, and improving the sealing performance of the mouth ring.

Description

Technical Field

[0001] The invention relates to the technical field of multi-stage submersible pumps, and in particular to an impeller assembly for a multi-stage submersible pump. Background Art

[0002] Submersible pumps are important equipment for deep well water extraction. They are often used in water extraction projects such as rivers, reservoirs, and canals, farmland irrigation, and water for people and livestock in mountainous areas. They can also be used for central air conditioning cooling, heat pump units, cold pump units, cities, factories, railways, mines, and construction site drainage. They are composed of four major parts: water pumps, submersible motors, water pipes, and control switches. The water pump includes a pump shaft connected to the submersible motor and an impeller arranged on the pump shaft. Multi-stage submersible pumps are generally composed of 2-4 sets of impellers. The impeller includes a pump casing and an impeller and guide vanes arranged in the pump casing. During the operation of the impeller, the liquid enters the impeller flow channel composed of the front cover plate, blades, and rear cover plate from the suction port of the impeller. When the liquid passes through the impeller flow channel, the impeller does work on the liquid and transfers part of the energy to the liquid. However, high-lift submersible pumps will generate centripetal force during operation. Conventional multi-stage submersible pumps fix the impeller on the pump shaft in series, and the rotor bears the axial force generated by the impeller when it is working. Small multi-stage submersible electric pumps generally use balancing holes, thrust bearings, and water-lubricated thrust bearing structures to balance the axial force, but these methods may cause bearing damage and require frequent replacement of bearings and balancing plates, which is time-consuming and labor-intensive.

[0003] To this end, Chinese utility model patent CN211039076U provides a floating impeller multi-stage submersible pump, which consists of a submersible motor, a water inlet section, a pump casing, an impeller, a pump shaft and a pump outlet. The submersible motor is connected to the pump shaft, and each stage of the impeller is installed in the corresponding pump casing. The impeller can slide axially on the pump shaft. A front thrust washer is installed on the front cover plate of each stage of the impeller, and a rear thrust washer is installed on each stage of the impeller. The impeller transmits the axial force generated during operation to the pump casing through the thrust washer. The guide vane holes of the impeller hub and the pump casing are designed to be longer than those of conventional pumps. Due to the use of an axial unloading and radial straightening structure, the impeller slides on the shaft during operation, and the axial force generated is transmitted from the impeller to the pump casing. The axial force borne by the shaft is reduced to a certain extent, thereby avoiding the damage of the axial force to the bearing, so as to improve the service life of the small multi-stage submersible electric pump. However, the above-mentioned floating impeller multi-stage submersible pump has the following disadvantages:

[0004] (1) The axial force is transmitted to the pump casing through the thrust washer. The guide vane holes of the impeller hub and the pump casing are long, which affects the floating performance of the impeller. The floating bearing effect of the axial force is poor.

[0005] (2) The impeller is machined with an impeller ring, which is matched with the pump casing ring hole clearance. When the impeller is running, there is severe wear between the impeller ring and the pump casing. The impeller ring mainly plays a sealing role to prevent the outlet medium from flowing back to the inlet. The wear of the ring will cause the ring gap to increase, affecting the sealing performance of the ring.

[0006] In view of this, it is urgent to improve the structure of the impeller for the multi-stage submersible pump in order to improve the balancing effect of the impeller axial force and reduce the wear between the impeller mouth ring and the pump casing. Summary of the invention

[0007] The technical problem to be solved by the present invention is that the existing multi-stage submersible pump impeller has poor axial force balancing effect, the impeller mouth ring is seriously worn, and the sealing performance of the mouth ring is affected.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0009] An impeller assembly for a multi-stage submersible pump comprises an impeller shell, wherein the impeller shell is provided with:

[0010] The impeller is sleeved on the pump shaft and can slide along the axial direction of the pump shaft. The lower end of the impeller is provided with a liquid inlet, and the fluid medium enters the impeller through the liquid inlet. The impeller is provided with a liquid flow channel connected with the liquid inlet;

[0011] A guide vane is arranged above the impeller and is inserted and fixed with the impeller shell. A liquid outlet cavity communicating with the liquid flow channel is formed between the impeller and the impeller shell. A liquid outlet is arranged on the top surface of the impeller shell and is communicated with the liquid outlet cavity. The impeller shell is floatingly sleeved on the pump shaft.

[0012] The mouth ring is movably arranged between the outer side surface of the liquid inlet portion and the inner side surface of the impeller shell through a mouth ring seat.

[0013] In this solution, the impeller includes:

[0014] A hub, sleeved on the pump shaft, with its inner side adapted to the pump shaft;

[0015] An upper cover plate and a lower cover plate are arranged on the upper part of the hub, blades are arranged on the opposite ends of the upper cover plate and the lower cover plate, and the upper cover plate, the lower cover plate and the blades form a liquid flow channel;

[0016] The liquid inlet portion is cylindrical, is arranged on the bottom surface of the lower cover plate, and is communicated with the liquid flow channel.

[0017] In this solution, the impeller shell includes:

[0018] The lower impeller shell is a hollow cylindrical impeller shell, the upper part of the inner wall of which extends inward to form a guide vane seat, the center of the guide vane seat is provided with an impeller hole, the impeller is rotatably arranged in the impeller hole; the top surface of the guide vane seat is provided with a guide vane mounting hole, the guide vane is inserted in the guide vane mounting hole; the lower part of the inner wall of the lower impeller shell and the impeller form a liquid inlet cavity, the mouth ring is arranged in the liquid inlet cavity through the mouth ring seat;

[0019] The upper impeller shell has a liquid outlet on its top surface, the hub of the next-stage impeller assembly is inserted into the liquid outlet of the previous-stage impeller assembly, and the liquid inlet of the next-stage impeller assembly is arranged opposite to the liquid outlet of the previous-stage impeller assembly.

[0020] In this solution, the guide vane includes:

[0021] A conical disk, the top surface of which is provided with anti-guide vanes in radial direction, the anti-guide vanes are arranged opposite to the upper impeller shell to form a guide channel, and the guide channel is connected with the liquid outlet cavity and the liquid outlet;

[0022] Positive guide vane blades are arranged at equal intervals on the bottom edge of the conical disk, and the lower ends of the positive guide vane blades are inserted into the guide vane mounting holes. A pressure relief port is formed between two adjacent positive guide vane blades, and the pressure relief port connects the liquid flow channel and the liquid outlet cavity.

[0023] In the present embodiment, the mouth ring seat is an annular seat, whose inner side surface is matched with the outer side surface of the liquid inlet portion, and whose outer side surface is matched with the inner side surface of the lower impeller shell. A mouth ring groove is provided on the top surface of the mouth ring seat on the side close to the inner side surface, and the mouth ring is arranged in the mouth ring groove, and the outer diameter of the mouth ring groove is larger than the outer diameter of the mouth ring.

[0024] In this solution, a stainless steel impeller sheath is provided on the liquid inlet portion.

[0025] In this solution, a lower stop bearing is arranged at the bottom end of the hub, and an upper thrust bearing is arranged at the top end of the guide vane.

[0026] In this solution, the pump shaft is a prismatic shaft.

[0027] In this solution, there is a space for movement between the conical disk and the upper cover plate.

[0028] In this solution, the depth of the mouth ring groove is greater than the thickness of the mouth ring.

[0029] Compared with the prior art, the impeller assembly for a multi-stage submersible pump provided by the present invention includes an impeller shell, an impeller, a guide vane and a mouth ring arranged in the impeller shell, the impeller is sleeved on the pump shaft and can slide along the axial direction of the pump shaft, the guide vane is arranged above the impeller, and the floating sleeve is arranged on the pump shaft. The guide vane can carry the axial force generated by the operation of the impeller through eccentric or inclined floating, thereby improving the balancing effect of the axial force. In the present invention, the mouth ring is movably arranged between the impeller and the pump shell through the mouth ring seat, so as to avoid wear between the impeller and the pump shell and increase the impeller clearance, thereby improving the sealing performance of the mouth ring and the operating efficiency of the submersible pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a structural breakdown diagram of the impeller assembly in the present invention;

[0031] Figure 2 is a cross-sectional view of the impeller assembly of the present invention;

[0032] Figure 3 is a cross-sectional view of a multi-stage impeller assembly in the present invention;

[0033] Figure 4 It is a structural schematic diagram of the guide vane in the present invention;

[0034] Figure 5 It is a schematic diagram of the structure of the impeller in the present invention.

[0035] in, Figures 1 to 5 The corresponding relationship between the reference numerals and component names is as follows:

[0036] 2 impeller, 3 guide vane, 4 ring, 5 ring seat, 21 hub, 22 upper cover plate, 23 lower cover plate, 24 liquid inlet, 210 lower thrust bearing, 25 blade, 26 liquid flow channel, 27 liquid outlet cavity, 28 stainless steel impeller sleeve, 11 upper impeller shell, 12 lower impeller shell, 121 guide vane seat, 122 impeller hole, 123 guide vane mounting hole, 124 liquid inlet cavity, 110 liquid outlet, 31 conical disk, 32 positive guide vane blade, 310 reverse guide vane, 311 guide channel, 312 upper thrust bearing, 33 pressure relief port, 51 ring groove. DETAILED DESCRIPTION

[0037] The present invention provides an impeller assembly for a multi-stage submersible pump, which improves the balancing effect of the axial force of the impeller by bearing the axial force generated by the rotation of the impeller through the guide vane floatingly arranged on the pump shaft; the mouth ring is movably arranged through the mouth ring seat, which avoids the wear between the mouth ring and the impeller and the pump casing, thereby preventing the mouth ring gap from increasing, and improving the sealing performance of the mouth ring. The present invention is described in detail below in conjunction with the drawings and specific embodiments of the specification.

[0038] like Figure 1 , Figure 2 and Figure 3As shown, the present invention provides an impeller mechanism assembly for a multi-stage submersible pump, comprising an impeller shell, an impeller 2, a guide vane 3 and a mouth ring 4 arranged in the impeller shell, the guide vane 3 is inserted on the impeller shell, and the floating sleeve is arranged on the pump shaft. The impeller 2 is arranged below the guide vane 3 and can slide along the axial direction of the pump shaft. The mouth ring 4 is movably arranged between the impeller 2 and the impeller shell through the mouth ring seat 5.

[0039] like Figure 1 and Figure 5 As shown, the impeller 2 includes a hub 21, an upper cover plate 22, a lower cover plate 23 and a liquid inlet 24. The hub 21 is used to be sleeved on the pump shaft and adapted to the pump shaft. The pump shaft is a prismatic shaft. A lower thrust bearing 210 is provided at the bottom end of the hub 21. The upper cover plate 22 and the lower cover plate 23 are sleeved on the upper end of the hub 21. Blades 25 are provided on the opposite ends of the upper cover plate 22 and the lower cover plate 23. The upper cover plate 22 and the lower cover plate 23 and the blades 25 form a liquid flow channel 26. The liquid inlet 24 is cylindrical, arranged on the bottom surface of the lower cover plate 23, and communicated with the liquid flow channel 26. The upper cover plate 22 and the lower cover plate 23 of the impeller 2 and the impeller shell form a liquid outlet cavity 27, and the liquid outlet cavity 27 is communicated with the liquid flow channel 26. A stainless steel impeller sheath 28 is provided on the liquid inlet 24 to prevent the liquid inlet 24 on the impeller 2 from being worn.

[0040] The impeller shell includes an upper impeller shell and a lower impeller shell 2. The lower impeller shell 2 is a hollow cylindrical impeller shell, and the upper part of the inner wall thereof extends inward to form a guide vane seat 121. The center of the guide vane seat 121 is provided with an impeller hole 122, and the impeller 2 is rotatably arranged in the impeller hole 122; the top surface of the guide vane seat 121 is provided with a guide vane mounting hole 123, and the guide vane 3 is inserted in the guide vane mounting hole 123; the lower part of the inner wall of the lower impeller shell 2 and the impeller 2 form a liquid inlet cavity 124, and the mouth ring 4 is arranged in the liquid inlet cavity 124 through the mouth ring seat 5. The top surface of the upper impeller shell is provided with a liquid outlet 110.

[0041] like Figure 4As shown, the guide vane 3 includes a conical disc 31 and a positive guide vane 32. The conical disc 31 is sleeved on the pump shaft, and a reverse guide vane 310 is radially arranged on its top surface. The reverse guide vane 310 is arranged opposite to the inner wall of the upper impeller shell to form a guide channel 311. The guide channel 311 connects the liquid outlet cavity 27 and the liquid outlet 110. An upper thrust bearing 312 is arranged at the top of the conical disc 31. In a multi-stage submersible pump, the hub 21 of the next-stage impeller assembly is inserted into the liquid outlet 110 of the previous-stage impeller assembly, the liquid inlet 24 of the next-stage impeller assembly is arranged opposite to the liquid outlet 110 of the previous-stage impeller assembly, and the lower thrust bearing 210 is arranged opposite to the upper thrust bearing 312. There is a moving space between the bottom surface of the conical disc 31 and the top surface of the upper cover plate 22. The positive guide vane blades 32 are arranged on the bottom edge of the conical disk 31, and the positive guide vane blades 32 are arranged at equal intervals. The lower ends of the positive guide vane blades 32 are inserted into the guide vane mounting holes 123, and a pressure relief port 33 is formed between two adjacent positive guide vane blades 32, and the pressure relief port 33 connects the liquid flow channel 26 and the liquid outlet cavity 27.

[0042] The ring seat 5 is an annular seat, the inner side of which is matched with the outer side of the liquid inlet portion 24, and the outer side of which is matched with the inner side of the lower impeller shell 2. A ring groove 51 is provided on the top surface of the ring seat 5 near the inner side, and the ring 4 is arranged in the ring groove 5. The outer diameter of the ring groove 51 is larger than the outer diameter of the ring 4. The depth of the ring groove 51 is larger than the thickness of the ring 4.

[0043] The method of use (working process) of the present invention is as follows:

[0044] The impeller 2 is sleeved on the pump shaft. When the motor drives the pump shaft to rotate, the pump shaft drives the impeller 2 to rotate. The fluid medium enters the liquid flow channel 26 of the impeller 2 through the liquid inlet 24. As the impeller 2 rotates, due to the unbalanced upper and lower pressures of the upper cover plate 23 and the lower cover plate 24 of the impeller 2, an axial force parallel to the pump shaft direction and pointing to the liquid inlet 24 is generated. The axial force is transmitted to the upper thrust bearing 312 of the upper-stage guide vane 3 through the lower thrust bearing 210 on the hub 21. The upper-stage guide vane 3 is eccentric or slides according to the axial force transmitted by the upper thrust bearing 312, and the axial force is floatingly carried.

[0045] During the operation of the impeller 2, the fluid medium enters the liquid flow channel 26 from the liquid inlet 24, is discharged from the pressure relief port 33, and enters the liquid outlet cavity 27. The guide vane 3 is arranged above the impeller 2 and fixed to the lower impeller shell 2. After entering the liquid outlet cavity 27, the fluid medium enters the guide channel 311 on the conical disk 31, converts part of the kinetic energy of the water flow into pressure energy, and then enters the liquid inlet 24 of the next-stage impeller 2 through the liquid outlet 110 on the upper impeller shell. After the above-mentioned pressurization process, the fluid medium is pressurized step by step, and finally the fluid medium is pressurized and transported to the surface.

[0046] During the operation of the impeller 2, the mouth ring 4 is always pressed against the mouth ring seat 5 under the action of the interstage pressure to prevent the fluid medium in the liquid outlet cavity 27 from flowing out of the gap between the impeller 2 and the lower impeller shell 2. The mouth ring 4 is movably arranged in the mouth ring groove 51 on the mouth ring seat 5, and the position of the mouth ring 4 in the mouth ring groove 51 can be adjusted with the eccentricity or sliding of the impeller 2, so that the mouth ring 4 always maintains a sealed state.

[0047] Compared with the prior art, the impeller structure assembly for a multi-stage submersible pump provided by the present invention can realize multi-stage series connection, and the guide vane can bear the axial force generated by the operation of the impeller by eccentric or inclined floating, thereby improving the balancing effect of the axial force. In the present invention, the mouth ring is movably arranged between the impeller and the pump casing through the mouth ring seat, thereby avoiding wear between the impeller or the pump casing and causing an increase in the impeller clearance, thereby improving the sealing performance of the mouth ring and the operating efficiency of the submersible pump.

[0048] In this solution, the shape of the mouth ring groove is adapted to the outer side surface of the mouth ring, and the outer diameter of the mouth ring groove is larger than the outer diameter of the mouth ring, which facilitates the position of the mouth ring to be adjusted according to the impeller posture to achieve radial sealing.

[0049] In this solution, the depth of the mouth ring groove is greater than the thickness of the mouth ring, and there is a stringing space between the top of the mouth ring and the lower impeller shell, which makes it convenient for the mouth ring to float with the impact of water flow when the water pump starts, reduces the starting resistance of the water pump, and has good starting performance.

[0050] In this solution, there is a moving gap between the bottom surface of the conical disk on the guide vane and the top surface of the impeller cover plate, and there is a moving space between the guide vane floating bearing and the impeller hub bearing. Floating particles can flow in the moving space with the water flow, preventing the floating particles from clogging the gap between the impeller and the pump casing, causing the pump shaft to get stuck, thereby improving the sand resistance of the submersible pump.

[0051] In this solution, a split design is adopted between the guide vane and the pump casing composed of the impeller base and the guide vane cover, which is convenient for replacement according to the different wear conditions of each component, reduces maintenance costs and prolongs service life.

[0052] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone should be aware that any structural changes made under the inspiration of the present invention, and any technical solutions that are the same or similar to the present invention, fall within the protection scope of the present invention.

Claims

1. An impeller assembly for a multi-stage submersible pump, characterized in that: It includes an impeller housing, in which there are: The impeller is sleeved on the pump shaft and can slide along the axial direction of the pump shaft. The pump shaft is a prismatic shaft. A liquid inlet is arranged at the lower end of the impeller. A stainless steel impeller sheath is sleeved on the liquid inlet. The fluid medium enters the impeller through the liquid inlet. A liquid flow channel is arranged inside the impeller and is connected to the liquid inlet. The guide vane is arranged above the impeller and is fixed with the impeller shell. The top of the guide vane is provided with an upper thrust bearing. A liquid outlet cavity connected with the liquid flow channel is formed between the impeller and the impeller shell. A liquid outlet is arranged on the top surface of the impeller shell and is connected with the liquid outlet cavity. The floating sleeve of the impeller shell is arranged on the pump shaft. A mouth ring is movably arranged between the outer side surface of the liquid inlet portion and the inner side surface of the impeller shell through a mouth ring seat; The impeller includes: The wheel hub is sleeved on the pump shaft, the inner side of which is matched with the pump shaft, and the bottom end of the wheel hub is provided with a lower thrust bearing; An upper cover plate and a lower cover plate are arranged on the upper part of the hub, blades are arranged on the opposite ends of the upper cover plate and the lower cover plate, and the upper cover plate, the lower cover plate and the blades form a liquid flow channel; The liquid inlet portion is cylindrical, arranged on the bottom surface of the lower cover plate, and communicated with the liquid flow channel; The impeller housing consists of: The lower impeller shell is a hollow cylindrical impeller shell, the upper part of the inner wall of which extends inward to form a guide vane seat, the center of the guide vane seat is provided with an impeller hole, and the impeller is rotatably arranged in the impeller hole; the top surface of the guide vane seat is provided with a guide vane mounting hole, and the guide vane is inserted into the guide vane mounting hole; The upper impeller shell has a liquid outlet on its top surface, the hub of the next-stage impeller assembly is inserted into the liquid outlet of the previous-stage impeller assembly, and the liquid inlet of the next-stage impeller assembly is arranged opposite to the liquid outlet of the previous-stage impeller assembly; The guide vanes include: The conical disk has a radially arranged anti-guide blade on its top surface, which is arranged opposite to the upper impeller shell to form a guide channel, which connects the liquid outlet cavity and the liquid outlet, and there is a stringing space between the conical disk and the upper cover plate; Positive guide vane blades are arranged at equal intervals on the bottom edge of the conical disk, the lower ends of the positive guide vane blades are inserted into the guide vane mounting holes, and a pressure relief port is formed between two adjacent positive guide vane blades, and the pressure relief port is connected to the liquid flow channel and the liquid outlet cavity; The mouth ring seat is an annular seat, whose inner side surface is matched with the outer side surface of the liquid inlet part, and whose outer side surface is matched with the inner side surface of the lower impeller shell. The top surface of the mouth ring seat is provided with a mouth ring groove, and the mouth ring is arranged in the mouth ring groove. The outer diameter of the mouth ring groove is larger than the outer diameter of the mouth ring, and the depth of the mouth ring groove is larger than the thickness of the mouth ring.

2. The impeller assembly for a multi-stage submersible pump according to claim 1, characterized in that: The lower part of the inner wall of the lower impeller shell and the impeller form a liquid inlet cavity, and the mouth ring is arranged in the liquid inlet cavity through the mouth ring seat.

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