Energy-saving multi-stage pump

Abstract

The invention provides an energy-saving multi-stage pump which comprises a base assembly composed of a base, a driving assembly is installed on one side of a sealing cover assembly, a housing assembly is arranged between the sealing cover assembly and the base assembly, a flow guide mechanism is fixedly installed on the inner wall of the sealing cover assembly, the housing assembly comprises a flow guide part, an inner barrel and an outer barrel, and the inner barrel and the outer barrel are fixedly installed on the base assembly. A cavity for water source circulation is formed between the inner cylinder body and the outer cylinder body, a plurality of flow deflectors located in the cavity are fixedly installed on the inner wall of the outer cylinder body, and the tail ends of the flow deflectors and the flow guide holes are distributed correspondingly. Pressurized conveying of a transmission medium is achieved through the multi-stage pump, the arranged base assembly can be used for water source flow guiding, meanwhile, smooth circulation of a water source can be ensured through the base of a spiral structure, water source circulation is achieved through the flow guiding mechanism, the cavity is formed for water source discharging, and the multiple flow guiding pieces are arranged to achieve water source guiding; water flow can be gradually gathered to the flow collecting channel, the water flow speed and the follow-up lift can be improved under the same power, and the energy-saving performance of the multi-stage pump is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to an energy-saving multi-stage pump, belonging to the technical field of multi-stage pumps. BACKGROUND

[0002] The energy-saving multi-stage pump is a high-efficiency, energy-saving fluid conveying device, widely used in industrial, construction, agricultural and other fields. The energy-saving multi-stage pump works by connecting multiple impellers in series, gradually increasing the fluid pressure, thereby achieving high-pressure delivery. Its design optimizes hydraulic performance, reduces energy loss, and improves overall efficiency. It has the advantages of high efficiency and energy saving: advanced hydraulic model and optimized design are adopted to reduce energy consumption, which meets the national energy-saving standards; compact structure: the multi-stage pump is usually small in size, suitable for installation in space-limited environments; stable operation: low vibration and low noise design ensures long-term reliable operation and convenient maintenance; modular design facilitates disassembly and repair, etc. The multi-stage pump is a centrifugal pump that increases the lift (pressure) by connecting multiple impellers in series. It is widely used in high-pressure water supply, boiler feed water, petroleum and chemical industries, etc. The multi-stage pump increases the pressure by connecting impellers in series. Each stage of impeller converts liquid kinetic energy into pressure energy, and finally accumulates into high-lift output. The typical structure includes the suction section, the middle section (including the impeller), the guide vane and the discharge section. The more stages, the higher the lift. It has high lift: a single pump can reach hundreds to thousands of meters of lift, suitable for long-distance water delivery or high-pressure working conditions; efficiency optimization: by adjusting the number of stages to match the demand, the high energy consumption problem of single-stage pumps is avoided; compact design: horizontal split or segmented structure for easy maintenance, etc.

[0003] Common types include segmented multi-stage pumps (such as D-type): each stage of impeller is installed independently and fastened by tie rods, resistant to high pressure; horizontal split multi-stage pumps (such as GS-type): the casing is split along the axis for easy maintenance, suitable for large flow. It is mainly used in industrial fields: boiler feed water, chemical process pressurization, mine drainage; municipal engineering: high-rise building water supply, fire fighting system, water pipe network pressurization. Among them, stainless steel materials (such as 304 / 316) are required for conveying corrosive liquids; NPSH (net positive suction head): to prevent cavitation, the inlet pressure must be sufficient.

[0004] The multi-stage pump is a pump body structure that increases the delivery lift by multiple stages. It requires synchronous driving of multiple impellers to operate, so the power required to start the multi-stage pump is large. Long-term use increases energy consumption, reduces the energy-saving performance of the multi-stage pump, and the water flow in the multi-stage pump consumes a lot of energy. The impact on the multi-stage pump will affect the lift, and a larger power will be required to drive the multi-stage pump to achieve the corresponding lift, affecting the performance of the multi-stage pump. SUMMARY

[0005] The present application provides an energy-saving multi-stage pump to solve the technical problem of poor energy-saving performance of the multi-stage pump.

[0006] The present invention solves the above-mentioned technical problems through the following technical solutions: This invention provides an energy-saving multistage pump, the energy-saving multistage pump comprising: The base assembly consists of a base, with the two ends of the base fixedly connected to the inlet pipe and the outlet pipe, respectively. The inlet pipe and the outlet pipe are arranged in a spiral structure that is intertwined with each other. A drive assembly is installed on one side of the cover assembly. A housing assembly is provided between the cover assembly and the base assembly. A flow guiding mechanism is fixedly installed on the inner wall of the cover assembly. The housing assembly includes a flow guide, an inner cylinder, and an outer cylinder. The flow guide is fixedly installed on the base and is connected to the water inlet pipe. The flow guide is also fixedly connected to the inner cylinder. The outer cylinder is located outside the inner cylinder, and a cavity for water flow is formed between the inner and outer cylinders. Multiple flow guide plates located inside the cavity are fixedly installed on the inner wall of the outer cylinder. The tail ends of the flow guide plates are distributed corresponding to the flow guide holes. The flow guide holes are opened into the interior of the base, and the cavity is connected to the water outlet pipe through the flow guide holes.

[0007] In this technical solution, the water inlet pipe is provided with an inlet, and the inner wall of the water inlet pipe located at the inner end of the inlet is provided with an arc-shaped surface for guiding water flow. The water outlet pipe is provided with an outlet, and the inner end of the outlet is connected to the guide hole. The axes of the water inlet pipe and the water outlet pipe coincide with each other, and the far ends of the water inlet pipe and the water outlet pipe are connected to flanges for pipe installation.

[0008] In this technical solution, the cover assembly is composed of a rear cover. One side of the rear cover is fixedly connected to the inner cylinder and the outer cylinder respectively, and the other side of the rear cover is fixedly connected to the connecting plate. A mechanical seal is provided in the middle of the rear cover. The edges of the rear cover and the base are inserted through the pull rod. The pull rod is evenly arranged around the cover assembly, and the end of the pull rod is threaded with a nut.

[0009] In this technical solution, the drive assembly consists of a connecting plate and a motor. The motor is fixedly installed to one end of the connecting plate by a hexagonal bolt with a washer. The other end of the connecting plate is fixedly installed to the cover assembly. The output end of the motor is fixedly connected to a coupling by screws. The coupling is located inside the connecting plate, and the other end of the coupling is fixedly connected to a drive shaft. The drive shaft passes through the cover assembly and is connected to the base. The drive shaft is rotatably connected to the mechanical seal. Multiple evenly distributed impellers are fixedly installed on the surface of the drive shaft, and the multiple impellers are all arranged inside the cover assembly.

[0010] In this technical solution, one end of the drive shaft is connected to a bearing inner sleeve, the bearing inner sleeve is rotatably connected to the bearing outer sleeve, and the bearing outer sleeve is fixedly installed to the inner wall of the water inlet of the base. The bearing inner sleeve is fixedly connected to the shaft sleeve, and the shaft sleeve is fixedly connected to the drive shaft by a stud.

[0011] In this technical solution, the flow guide is an annular structure and fits to the edge of the water inlet of the base. The flow guide is fitted to the water inlet end of one of the impellers. The inner cylinder is spliced ​​and fixed by multiple annular metal plates. A flow guide shell is fixedly installed on the inner wall of each metal plate. The flow guide shell is set between the water inlet end of the impeller and the water outlet end of another impeller. The flow guide shell and the impeller form a flow guide channel that is interconnected. Multiple flow guide shells are sleeved on the surface of the drive shaft.

[0012] In this technical solution, one end of the outer cylinder is fixedly connected to the rear cover, and O-rings are fixedly connected to both ends of the outer cylinder. The O-rings are respectively set inside the base and the rear cover. A flow collection channel is formed at one end of the outer cylinder. The flow collection channel is located on one side of the guide plate, and the flow collection channel is connected to the water outlet through the guide hole.

[0013] In this technical solution, the flow guiding mechanism consists of a flow guiding shroud and a support plate. Both the flow guiding shroud and the support plate are fixedly installed on the inner wall of the rear cover. The flow guiding shroud is sleeved on the surface of the drive shaft, and one end of the flow guiding shroud extends to one side of the flow guiding shell. The flow guiding channels inside the flow guiding shell are distributed correspondingly to the surface of the flow guiding shroud. One end of the flow guiding shroud is provided with a protruding edge, which is fitted into the drive shaft.

[0014] In this technical solution, the flow guide is a bent structure located on the surface of the drive shaft. A sealing ring with an annular structure is fixedly connected to the inner wall of the flow guide. The sealing ring is movably sleeved with the surface of the drive shaft. The support plate is a bent annular structure. The middle part of the support plate contacts the flow guide, and one end of the support plate contacts the bent position of the flow guide.

[0015] In this technical solution, the inner cylinder is fixedly installed on the inner wall of the rear cover by clamping pads. A gap for water flow is formed between the inner cylinder and the rear cover. One end of the guide shroud extends into the gap. The outer surface of the inner cylinder contacts multiple guide vanes. The end of the guide vane near the gap is a horizontal structure, and the other end of the multiple guide vanes is an arc-shaped structure. The curvature of adjacent guide vanes gradually increases.

[0016] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0017] The positive and progressive effects of this invention are as follows: The aforementioned energy-saving multistage pump utilizes a multistage pump to pressurize and transport the medium. A base assembly is provided for water source guidance. The coaxial arrangement of the inlet and outlet facilitates pump installation, reducing the number of pipe joints. The spiral base ensures smooth water flow, and the resulting vortex flow is pressurized and transported by multiple impellers. A flow guiding mechanism further facilitates water flow, minimizing flow obstruction. A cavity is provided for water discharge, with multiple guide vanes within the cavity guiding the water flow towards the collection channel to increase velocity. This effectively prevents turbulence during backflow, which could limit velocity. The guided water can then be quickly discharged through the outlet, increasing flow velocity and subsequent head at the same power output, thus enhancing the energy-saving performance of the multistage pump. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the present invention.

[0019] Figure 2 This is a schematic diagram of the internal front view of the present invention.

[0020] Figure 3 This is a partial side view of the base structure of the present invention.

[0021] Figure 4 For the present invention Figure 2 A magnified schematic diagram of the structure at point A in the middle.

[0022] Figure 5 This is a schematic diagram of the overall internal structure of the present invention from the front.

[0023] Figure 6 This is a schematic diagram of the external partial front view of the structure of the present invention.

[0024] Figure 7 For the present invention Figure 2 A magnified schematic diagram of the structure at point B in the middle.

[0025] Figure 8 For the present invention Figure 2 A magnified schematic diagram of the structure at point C.

[0026] Figure 9 This is a three-dimensional structural diagram of the outer cylinder of the present invention.

[0027] Figure 10 This is a partial three-dimensional structural diagram of the guide plate of the present invention.

[0028] Explanation of reference numerals in the attached figures 100. Base assembly; 101. Base; 102. Water inlet pipe; 103. Water outlet pipe; 104. Curved surface; 105. Water inlet; 106. Water outlet; 200. Drive assembly; 201. Connecting disc; 202. Socket head bolt; 203. Motor; 204. Screw; 205. Coupling; 206. Drive shaft; 207. Bearing inner sleeve; 208. Shaft sleeve; 209. Stud; 210. Impeller; 300. Cover assembly; 301. Flow guide; 302. Inner cylinder; 303. Flow guide shell; 304. Flow guide channel; 305. Outer cylinder; 306. O-ring; 307. Flow guide plate; 308. Cavity; 309. Flow guide hole; 310. Flow collection channel; 400. Cover assembly; 401. Rear cover; 402. Mechanical seal; 403. Tie rod; 404. Nut; 405. Compression washer; 406. Clearance; 407. Shield; 408. Sealing ring; 409. Raised edge; 410. Support plate. Detailed Implementation

[0029] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0030] like Figures 1-10 As shown, the energy-saving multistage pump includes: The base assembly 100 is composed of a base 101. The two ends of the base 101 are fixedly connected to the water inlet pipe 102 and the water outlet pipe 103, respectively. The water inlet pipe 102 and the water outlet pipe 103 are distributed in a spiral structure that is intertwined with each other. A drive assembly 200 is installed on one side of a cover assembly 400. A cover assembly 300 is provided between the cover assembly 400 and the base assembly 100. A flow guiding mechanism is fixedly installed on the inner wall of the cover assembly 400. The housing assembly 300 includes a flow guide 301, an inner cylinder 302, and an outer cylinder 305. The flow guide 301 is fixedly installed on the base 101 and is connected to the water inlet pipe 102. The flow guide 301 is also fixedly connected to the inner cylinder 302. The outer cylinder 305 is located outside the inner cylinder 302. A cavity 308 for water flow is formed between the inner cylinder 302 and the outer cylinder 305. A plurality of flow guide plates 307 located inside the cavity 308 are fixedly installed on the inner wall of the outer cylinder 305. The tail ends of the flow guide plates 307 are distributed correspondingly to the flow guide holes 309. The flow guide holes 309 are opened into the interior of the base 101, and the cavity 308 is connected to the water outlet pipe 103 through the flow guide holes 309.

[0031] In this technical solution, the water source is pressurized and accelerated by multiple impellers 210 and then guided into the cavity 308 by the flow guiding mechanism. That is, it enters the cavity 308 evenly from the flow guide cover 407 through the gap 406. The water source entering the cavity 308 is diverted by the flow guide plate 307, so that the water source is guided by the flow guide plate 307 and then converges in a spiral shape at the collection channel 310. Since the collection channel 310 is located on one side of the annular cavity 308, after being guided by the flow guide plate 307, the water source will not generate turbulence and will overflow smoothly and quickly from the collection channel and the flow guide hole 309, thereby effectively reducing water flow loss and improving the energy-saving performance of the multi-stage pump.

[0032] The inlet pipe 102 is provided with an inlet 105. The inner wall of the inlet pipe 102 located at the inner end of the inlet 105 is provided with an arc-shaped surface 104 for guiding water flow. The outlet pipe 103 is provided with an outlet 106, and the inner end of the outlet 106 is connected to the guide hole 309. The axes of the inlet pipe 102 and the outlet pipe 103 coincide with each other. The far ends of the inlet pipe 102 and the outlet pipe 103 are connected to flanges for pipe installation.

[0033] In this technical solution, the flanges of the inlet pipe 102 and the outlet pipe 103 are used for pipe connection. The transmission medium enters through the inlet pipe 102 and exits through the outlet pipe 103. Since the flow direction of the inlet 105 and the outlet 106 is distributed in an intertwined spiral structure, the transmission medium is guided to increase the flow rate. At the same time, the arc-shaped surface 104 can be used to guide the transmission medium and minimize friction loss. The axes of the inlet pipe 102 and the outlet pipe 103 coincide. During subsequent installation, only a part of the pipe needs to be cut off and the flange can be used for installation without pipeline modification, ensuring installation convenience. By reducing the number of bends in the pipe, the problem of water flow obstruction can also be reduced.

[0034] The cover assembly 400 consists of a rear cover 401. One side of the rear cover 401 is fixedly connected to the inner cylinder 302 and the outer cylinder 305, respectively. The other side of the rear cover 401 is fixedly connected to the connecting plate. A mechanical seal 402 is provided in the middle of the rear cover 401. The edges of the rear cover 401 and the base 101 are both inserted through the pull rods 403. The pull rods 403 are evenly arranged around the cover assembly 300, and the ends of the pull rods 403 are threaded with nuts 404. The drive assembly 200 consists of a connecting plate 201 and a motor 203. The motor 203 is fixedly installed to one end of the connecting plate 201 by a socket head cap bolt 202 with a washer. The other end of the connecting plate 201 is fixedly installed to the cover assembly 400. The output end of the motor 203 is connected to a coupling by a screw 204. A coupling 205 is fixedly connected to a drive shaft 206 located within a connecting disc 201. The other end of the coupling 205 is fixedly connected to the drive shaft 206, which passes through the cover assembly 400 and connects to the base 101. The drive shaft 206 is rotatably connected to the mechanical seal 402. Multiple evenly distributed impellers 210 are fixedly mounted on the surface of the drive shaft 206, and all impellers 210 are located within the cover assembly 300. One end of the drive shaft 206 is connected to a bearing inner sleeve 207, which is rotatably connected to the bearing outer sleeve. The bearing outer sleeve is fixedly installed to the inner wall of the water inlet 105 of the base 101. The bearing inner sleeve 207 is fixedly connected to a bushing 208, which is fixedly connected to the drive shaft 206 via studs 209.

[0035] In this technical solution, the cover assembly 400 can be used for the installation of a multi-stage pump. The rear cover 401 is installed onto the inner cylinder 302 and outer cylinder 305 to achieve a seal, and a gap 406 for water flow transmission is formed between the rear cover 401 and the inner cylinder 302. A mechanical seal 402 is installed in the middle of the rear cover 401 to ensure stable rotation of the drive shaft 206 while preventing leakage. A flow guiding mechanism is also provided for water source diversion, which can effectively reduce the pressure at the mechanical seal 402 and reduce the risk of leakage. The drive shaft 206 achieves stable rotation through the inner bearing sleeve 207 and outer bearing sleeve at the other end, and multiple impellers 210 and guide shells 303 are installed to guide the water source. The water flow entering through the inlet 105 is guided by the high-speed rotating impellers 210. After a negative pressure is formed in the middle of the impeller 210, the water flow enters and is thrown out through the edge of the impeller 210 and enters the guide shell 303. After being guided by the guide shell 303, it enters the next impeller 210. Through multiple stages of transmission, the head is increased.

[0036] The flow guide 301 has an annular structure and is fitted to the edge of the inlet 105 of the base 101. The flow guide 301 is fitted to the inlet end of one of the impellers 210. The inner cylinder 302 is spliced ​​and fixed by multiple annular metal plates. A flow guide shell 303 is fixedly installed on the inner wall of each metal plate. The flow guide shell 303 is located between the inlet end of the impeller 210 and the outlet end of another impeller 210. The flow guide shell 303 and the impeller 210 both form a flow guide channel 304 that is interconnected. Multiple flow guide shells 303 are sleeved on the surface of the drive shaft 206.

[0037] In this technical solution, the inner cylinder 302, which is formed by splicing multiple annular metal plates, can be used to install multiple guide shells 303, which facilitates subsequent assembly and fixing. The multiple guide shells 303 are arranged between the impellers 210 to guide the water source discharged from the impellers 210, so that the transmission medium flows at high speed from the guide channel 304.

[0038] One end of the outer cylinder 305 is fixedly connected to the rear cover 401. Both ends of the outer cylinder 305 are fixedly connected with O-rings 306. The O-rings 306 are respectively disposed inside the base 101 and the rear cover 401. One end of the outer cylinder 305 forms a flow collection channel 310. The flow collection channel 310 is located on one side of the guide plate 307, and the flow collection channel 310 is connected to the outlet 106 through the guide hole 309.

[0039] In this technical solution, O-rings 306 are provided at both ends of the outer cylinder 305 for installation of the outer cylinder 305, improving the sealing performance at the connection between the outer cylinder 305 and the base 101 and the rear cover 401. A cavity 308 is formed between the outer cylinder 305 and the inner cylinder 302 for water conservancy and transportation. The water in the cavity 308 flows through the collection channel 310 and then enters the outlet 106 through the guide hole 309 for discharge, realizing efficient discharge of water source.

[0040] The flow guiding mechanism consists of a flow guide shroud 407 and a support plate 410. Both the flow guide shroud 407 and the support plate 410 are fixedly installed to the inner wall of the rear cover 401. The flow guide shroud 407 is sleeved on the surface of the drive shaft 206, and one end of the flow guide shroud 407 extends to one side of the flow guide shell 303. The flow guiding channels 304 inside the flow guide shell 303 are correspondingly distributed on the surface of the flow guide shroud 407. One end of the flow guide shroud 407 is provided with a protruding edge 409, which is fitted into the drive shaft 206. When the drive shaft 206 rotates, it will not interfere with the flow guide shroud 407. 7. Intervention: When the flow guide 407 deforms, the sealing ring 408 can effectively fit against the surface of the drive shaft 206. The flow guide 407 is a bent structure and is located on the surface of the drive shaft 206. The inner wall of the flow guide 407 is fixedly connected with a ring-shaped sealing ring 408. The sealing ring 408 is movably sleeved with the surface of the drive shaft 206. The support plate 410 is a bent ring structure. The middle part of the support plate 410 contacts the flow guide 407, and one end of the support plate 410 contacts the bent position of the flow guide 407.

[0041] In this technical solution, the water flow discharged through the last guide shell 303 will pass through the guide mechanism. After being guided by the guide mechanism, the water flow will enter the cavity 308 from the gap 406. This can guide the water flow to reduce water flow velocity loss and reduce the impact of water flow pressure on the mechanical seal 402, effectively reducing the risk of leakage.

[0042] Furthermore, when the water discharged from the guide shell 303 impacts the guide cover 407, it is redirected by the guide cover 407. At the same time, the impact force on the guide cover 407 causes it to bend and deform, and the guide cover 407 will abut against the support plate 410 of the bent structure. After being subjected to force, the support plate 410 bends so that one end abuts against the guide cover 407, and the guide cover 407 sleeved on the drive shaft 206 deforms, thereby making the sealing ring 408 fit tightly against the drive shaft 206, which can further improve the sealing performance.

[0043] The inner cylinder 302 is fixedly installed on the inner wall of the rear cover 401 by clamping pads 405. A gap 406 for water flow is formed between the inner cylinder 302 and the rear cover 401. One end of the flow guide shroud 407 extends into the gap 406. The outer surface of the inner cylinder 302 is in contact with multiple flow guide plates 307. The end of the flow guide plate 307 near the gap 406 is a horizontal structure, and the other end of the multiple flow guide plates 307 is an arc structure. The curvature of adjacent flow guide plates 307 gradually increases.

[0044] In this technical solution, the inner cylinder 302 is fixed to the rear cover 401 by clamping pads 405, forming a gap 406 between the inner cylinder 302 and the rear cover 401 to facilitate water supply. Water enters the cavity 308 evenly from the guide shroud 407 through the gap 406. At this time, the water entering the multiple guide vanes 307 is separated by the guide vanes 307. The guide vanes 307 that are close to the collection channel 310 have a smaller curvature, thus having less interference with the water supply guidance and being further away from the collection channel. The curvature of the guide vanes 307 in channel 310 gradually increases, and the far ends of the guide vanes 307 correspond to the collection channel 310. This allows the water source to be guided by multiple guide vanes 307 and then concentrated for transmission within the collection channel 310. This prevents dead zones inside the cavity 308 from causing turbulence and avoids eddies in the water source within the cavity 308 that could affect the transmission speed. This effectively improves the water source delivery efficiency and, consequently, increases the head under the same power, thereby improving the energy-saving performance of the multistage pump.

[0045] This invention is not limited to the embodiments described above. Any changes in shape or structure shall fall within the protection scope of this invention. The protection scope of this invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of this invention, but all such changes and modifications shall fall within the protection scope of this invention.

Claims

1. An energy-saving multistage pump, characterized in that, The energy-saving multistage pump includes: The base assembly (100) is composed of a base (101). The two ends of the base (101) are fixedly connected to the water inlet pipe (102) and the water outlet pipe (103) respectively. The water inlet pipe (102) and the water outlet pipe (103) are distributed in a spiral structure that is intertwined with each other. A drive assembly (200) is installed on one side of a cover assembly (400), and a cover assembly (300) is provided between the cover assembly (400) and the base assembly (100). A flow guiding mechanism is fixedly installed on the inner wall of the cover assembly (400). The housing assembly (300) includes a flow guide (301), an inner cylinder (302), and an outer cylinder (305). The flow guide (301) is fixedly mounted on the base (101), and the flow guide (301) is connected to the water inlet pipe (102). The flow guide (301) is also fixedly connected to the inner cylinder (302). The outer cylinder (305) is located outside the inner cylinder (302). The inner cylinder (302) and the outer cylinder... A cavity (308) for water flow is formed between the bodies (305). Multiple guide vanes (307) located inside the cavity (308) are fixedly installed on the inner wall of the outer cylinder (305). The tail ends of the guide vanes (307) are distributed correspondingly to the guide holes (309). The guide holes (309) are opened to the inside of the base (101), and the cavity (308) is connected to the water outlet pipe (103) through the guide holes (309).

2. The energy-saving multistage pump as described in claim 1, characterized in that: The inlet pipe (102) is provided with an inlet (105), and the inner wall of the inlet pipe (102) located at the inner end of the inlet (105) is provided with an arc-shaped surface (104) for guiding water flow. The outlet pipe (103) is provided with an outlet (106), and the inner end of the outlet (106) is connected to the guide hole (309). The axes of the inlet pipe (102) and the outlet pipe (103) coincide with each other. The far ends of the inlet pipe (102) and the outlet pipe (103) are connected to flanges for pipe installation.

3. The energy-saving multistage pump as described in claim 1, characterized in that: The cover assembly (400) consists of a rear cover (401). One side of the rear cover (401) is fixedly connected to the inner cylinder (302) and the outer cylinder (305) respectively. The other side of the rear cover (401) is fixedly connected to the connecting plate. A mechanical seal (402) is provided in the middle of the rear cover (401). The edges of the rear cover (401) and the base (101) are inserted through the pull rod (403). The pull rod (403) is evenly arranged around the cover assembly (300), and a nut (404) is threaded to the end of the pull rod (403).

4. The energy-saving multistage pump as described in claim 3, characterized in that: The drive assembly (200) consists of a connecting plate (201) and a motor (203). The motor (203) is fixedly installed to one end of the connecting plate (201) by a socket head cap bolt (202) with a washer. The other end of the connecting plate (201) is fixedly installed to the cover assembly (400). The output end of the motor (203) is fixedly connected to the coupling (205) by a screw (204). The coupling (205) is located inside the connecting plate (201), and the other end of the coupling (205) is fixedly connected to the drive shaft (206). The drive shaft (206) passes through the cover assembly (400) and is connected to the base (101). The drive shaft (206) is rotatably connected to the mechanical seal (402). Multiple evenly distributed impellers (210) are fixedly installed on the surface of the drive shaft (206). All the impellers (210) are located inside the cover assembly (300).

5. The energy-saving multistage pump as described in claim 4, characterized in that: One end of the drive shaft (206) is connected to a bearing inner sleeve (207), the bearing inner sleeve (207) is rotatably connected to the bearing outer sleeve, and the bearing outer sleeve is fixedly installed to the inner wall of the water inlet (105) of the base (101). The bearing inner sleeve (207) is fixedly connected to the bushing (208), and the bushing (208) is fixedly connected to the drive shaft (206) by a stud (209).

6. The energy-saving multistage pump as described in claim 1, characterized in that: The guide element (301) is an annular structure and fits to the edge of the inlet (105) of the base (101). The guide element (301) fits to the inlet end of one of the impellers (210). The inner cylinder (302) is spliced ​​and fixed by multiple annular metal plates. Each metal plate has a guide shell (303) fixedly installed on its inner wall. The guide shell (303) is set between the inlet end of the impeller (210) and the outlet end of the other impeller (210). The guide shell (303) and the impeller (210) form a guide channel (304) that is interconnected. Multiple guide shells (303) are sleeved on the surface of the drive shaft (206).

7. The energy-saving multistage pump as described in claim 1, characterized in that: One end of the outer cylinder (305) is fixedly connected to the rear cover (401). Both ends of the outer cylinder (305) are fixedly connected with O-rings (306). The O-rings (306) are respectively set inside the base (101) and the rear cover (401). One end of the outer cylinder (305) forms a flow collection channel (310). The flow collection channel (310) is located on one side of the guide plate (307), and the flow collection channel (310) is connected to the outlet (106) through the guide hole (309).

8. The energy-saving multistage pump as described in claim 1, characterized in that: The flow guiding mechanism consists of a flow guide shroud (407) and a support plate (410). The flow guide shroud (407) and the support plate (410) are both fixedly installed on the inner wall of the rear cover (401). The flow guide shroud (407) is sleeved on the surface of the drive shaft (206), and one end of the flow guide shroud (407) extends to one side of the flow guide shell (303). The flow guiding channel (304) inside the flow guide shell (303) is distributed correspondingly to the surface of the flow guide shroud (407). One end of the flow guide shroud (407) is provided with a protruding edge (409), which is fitted into the drive shaft (206).

9. The energy-saving multistage pump as described in claim 8, characterized in that: The flow guide (407) is a bent structure and is located on the surface of the drive shaft (206). A ring-shaped sealing ring (408) is fixedly connected to the inner wall of the flow guide (407). The sealing ring (408) is movably sleeved with the surface of the drive shaft (206). The support plate (410) is a bent ring structure. The middle part of the support plate (410) is in contact with the flow guide (407), and one end of the support plate (410) is in contact with the bent position of the flow guide (407).

10. The energy-saving multistage pump as described in claim 1, characterized in that: The inner cylinder (302) is fixedly installed on the inner wall of the rear cover (401) by clamping pads (405). A gap (406) for water flow is formed between the inner cylinder (302) and the rear cover (401). One end of the flow guide (407) extends into the gap (406). The outer surface of the inner cylinder (302) is in contact with multiple flow guides (307). The end of the flow guide (307) near the gap (406) is horizontal, and the other end of the multiple flow guides (307) is arc-shaped. The curvature of adjacent flow guides (307) gradually increases.

Images