High-lift multistage impeller pump

Abstract

The utility model discloses a high-lift multi-stage impeller pump, and belongs to the field of impeller pumps. The front guide vane part is coaxially arranged in the last-stage guide vane, and the multiple sets of positive guide vanes are arranged in the middle, corresponding to the impeller, of the front guide vane part in a surrounding mode and used for guiding liquid thrown out by the impeller to the water outlet. The front end of the front guide vane part and the inner wall of the last-stage guide vane are positioned in a clearance fit mode in the axial direction and the radial direction, and the tail end of the front guide vane part is fixedly connected with the front bearing seat. The guide vane structure and the impeller structure are matched and optimized, so that the lift performance and the hydraulic efficiency of the pump body can be further improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to impeller pump technical field, more specifically, relate to a high-lift multistage impeller pump. BACKGROUND

[0002] With the expansion of industrial system scale and the improvement of energy efficiency requirements, the demand for high-lift pumps in the fields of energy transportation, deep well operation and high-pressure fluid treatment is increasingly prominent. The traditional single-stage centrifugal pump is limited by the work capacity of the single-stage impeller, and its lift is usually difficult to break through 200 meters, and the efficiency decreases significantly as the lift increases. To meet the demand for high-pressure delivery, multistage impeller pumps increase pressure by connecting multiple impellers, becoming the mainstream technical solution to achieve kilometer lift.

[0003] To achieve higher lift in a limited volume, a guide vane structure is introduced into the design of the multistage pump. The guide vane assembly is fitted around the periphery of the impeller and is provided with guide vanes. The high-speed fluid kinetic energy output by the front-stage impeller can be converted into pressure energy through the guide vanes, and the regular flow is then input into the rear-stage impeller, reducing the inter-stage efficiency loss. The design of the guide vane structure varies greatly, and how to optimize the design of the guide vane structure to better cooperate with the impeller mechanism and improve the lift and efficiency of the pump body has always been a concern in the industry. SUMMARY

[0004] 1. Technical problem to be solved by the utility model

[0005] In view of the higher demand for pump body lift and hydraulic efficiency in the prior art, the utility model provides a high-lift multistage impeller pump. Through the optimization of the cooperation between the guide vane structure and the impeller structure, the lift performance and hydraulic efficiency of the pump body can be further improved.

[0006] 2. Technical solution

[0007] To achieve the above-mentioned purpose, the utility model provides the technical scheme as follows:

[0008] The high-lift multistage impeller pump of the utility model comprises a base, a pump shell, and a front bearing seat compressed between the base and the pump shell. A plurality of stages of cooperating impellers and guide vane assemblies are arranged around the periphery of the pump shaft in the pump shell. The multistage guide vane assembly comprises at least a last-stage guide vane. A plurality of water outlets are arranged on the outer peripheral wall of the last-stage guide vane corresponding to the position of the last-stage impeller. The axial tail end of the last-stage guide vane is positioned against the front bearing seat, and the axial front end of the last-stage guide vane is positioned against the front-stage guide vane assembly.

[0009] A front guide vane part is coaxially arranged inside the last-stage guide vane. A plurality of positive guide vanes are arranged around the middle part of the front guide vane part corresponding to the impeller. The positive guide vanes are used to guide the liquid thrown out by the impeller to the water outlets. The front end of the front guide vane part and the inner wall of the last-stage guide vane are positioned with a gap in the axial and radial directions. The tail end of the front guide vane part is fixedly connected to the front bearing seat.

[0010] Further, the cooperation gap between the front end of the front guide vane part and the inner wall of the last guide vane is ≥0.5mm in the axial direction and 0.02-0.2mm in the radial direction.

[0011] Further, the tail end of the front guide vane part is provided with a fixed wall abutting the wall surface of the front bearing seat, and a plurality of sets of fastening bolts are arranged around the fixed wall to be fixedly connected with the front bearing seat.

[0012] Further, the front bearing seat comprises an inner body part, an axial hole is formed in the middle of the inner body part to install the pump shaft, an axially extending third convex ring part is arranged on the wall surface of the side of the inner body part facing the front guide vane part, the tail end of the front guide vane part is correspondingly provided with a protruding part embedded in the third convex ring part in the axial direction, and the tail end of the protruding part is provided with a radially extending fixed wall fixedly connected with the inner body part.

[0013] Further, the last guide vane comprises an outer ring body part, the installation space of the impeller and the front guide vane part is formed in the outer ring body part, and the water outlet is formed on the outer ring body part; the front end of the outer ring body part has guide vane blades correspondingly extending into the outer ring body part of the front stage guide vane assembly and cooperating with the front stage impeller; the tail end of the outer ring body part is inwardly bent to form a bent part two, the outer wall surface of the bent part two has a flat part, and the flat part is in contact with the wall surface of the front bearing seat to be positioned.

[0014] Further, the roughness of the flat part on the bent part two is less than 3.2, the perpendicularity of the flat part reaches 7-9 levels, and the flatness level of the flat part is less than the perpendicularity level.

[0015] Further, the front end of the outer ring body part is inwardly bent to form a bent part one, the bent part one is connected with the assembly ring part, the front end of the assembly ring part has a front end cover, the guide vane blades on the guide vane assembly are installed in front of the front end cover; an arc transition part is formed between the bent part one and the outer ring body part, and the arc transition part is in abutting positioning with the flat part of the bent part two of the front stage guide vane assembly.

[0016] Further, the front guide vane part is provided with an axial extension ring in front of the guide vane blades, the axial extension ring corresponds to the inner wall position of the assembly ring part of the last guide vane and is in radial gap cooperation.

[0017] Further, the front end of the axial extension ring is inwardly bent to form a radial extension ring, the radial extension ring is in axial gap cooperation with the front end cover of the last guide vane.

[0018] Further, the tail end of the bent part two is inwardly bent in the axial direction to form an inner stop ring, the inner body part of the front bearing seat is further provided with an axially protruding second convex ring part outside the third convex ring part, the second convex ring part correspondingly extends into the inner stop ring and is in radial gap cooperation.

[0019] 3. Advantageous effects

[0020] Compared with the prior art, the technical solution provided by this utility model has the following advantages:

[0021] This impeller pump, in its design, still features an independent guide vane structure within the final stage guide vane. This further regulates the flow direction of the water after multi-stage pressurization, ensuring accurate and rapid discharge to the high-pressure zone through multiple outlets, thereby achieving hydraulic boosting and improving the pump's head performance. Furthermore, the multi-stage guide vane assembly is installed axially and sequentially against each other within the pump body. A clearance fit is maintained between the additional guide vane in the final stage and the final stage guide vane in both the axial and radial directions, preventing double positioning of the final stage guide vane. This ensures accurate positioning and sealing of the final stage guide vane, reducing efficiency loss. In this configuration, fasteners are used to secure the additional guide vane to the front bearing housing. While maintaining a clearance fit at the front end, this ensures the stability of the additional guide vane's position, preventing internal mispositioning, vibration, abnormal noise, and disruption of normal pump operation, thus guaranteeing long-term reliable pump operation. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the pump unit in the embodiment;

[0023] Figure 2 This is a schematic diagram of the internal cross-sectional structure of the pump unit in the embodiment;

[0024] Figure 3 for Figure 2 A magnified schematic diagram of the partial structure at point A in the middle;

[0025] Figure 4 This is a schematic diagram of the front bearing housing in the embodiment;

[0026] Figure 5 This is a schematic diagram of the explosion state of the multi-stage guide vane assembly in the embodiment;

[0027] Figure 6 This is a schematic diagram of the intermediate guide vane structure in the embodiment;

[0028] Figure 7 This is a schematic cross-sectional view of the intermediate guide vane in the embodiment;

[0029] Figure 8 This is a schematic diagram of the structure of the last stage guide vane in the embodiment;

[0030] Figure 9 This is a cross-sectional view of the assembly state of the last stage guide vane and the front bearing housing in the embodiment.

[0031] Figure 10 for Figure 9 A schematic diagram of the structure from the perspective of the viewpoint.

[0032] Explanation of the labels in the diagram:

[0033] 100. Pump base; 102. Pump shaft; 200. Pump casing;

[0034] 300, First-stage guide vane; 310, Intermediate guide vane; 320, Last-stage guide vane; 330, Leading vane section;

[0035] 301. Outer ring body; 302. Bending part one; 303. Assembly ring part; 304. Front end cover; 305. Bending part two; 306. Inner stop ring;

[0036] 311. Anti-guide blade; 312. Forward guide blade; 313. Front connecting wall; 314. Shaft extension ring; 315. Radial extension ring; 316. Rear connecting wall; 317. Protrusion; 318. Fixed wall; 321. Outlet; 331. Fastening bolt;

[0037] 400. Front bearing housing; 401. Inner main body; 402. Shaft hole; 403. Third convex ring; 404. Second convex ring; 405. Outer main body; 406. Third convex ring; 407. Outer edge;

[0038] 500. Impeller. Detailed Implementation

[0039] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings.

[0040] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0041] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can be mechanical connections or electrical connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection of two components. The terms "first," "second," "third," and "fourth" should also be interpreted broadly, merely distinguishing feature names and not indicating a specific sequential relationship. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0042] The present invention will be further described below with reference to the embodiments.

[0043] Example

[0044] Combination Figures 1-10 As shown, this embodiment of a high-lift multistage impeller pump includes a base 100, a pump casing 200, and a front bearing housing 400 pressed between the base 100 and the pump casing 200. Multiple stages of cooperating impellers 500 and guide vane assemblies are arranged around the outer periphery of the pump shaft 102 within the pump casing 200. Specifically, the pump shaft 102 is installed within the base 100, passing through the front bearing housing 400 and extending into the pump casing 200. Rotor assemblies, stator assemblies, and other power components are also arranged around the pump shaft 102 within the base 100. Multiple stages of impellers 500 and guide vane assemblies, and other transmission components, are arranged around the pump shaft 102 within the pump casing 200. Typically, the impellers 500 are mounted on the pump shaft 102 and rotate with it, while the guide vane assemblies are fitted onto the outer side of the impellers 500, regulating the flow of liquid and transmitting it to the next stage impeller 500. The matching arrangement of the guide vane assemblies and impellers 500 is now widely used.

[0045] Combination Figure 2 and Figure 3 As shown, this embodiment takes a three-stage guide vane assembly as an example. The multi-stage guide vane assembly includes a first-stage guide vane 300, intermediate guide vanes 310, and a final-stage guide vane 320. When there are more stages, there are more sets of intermediate guide vanes 310. The intermediate guide vanes 310 and the final-stage guide vanes 320 have similar structures, both including a rear outer ring body 301 and a guide vane section located in front of the outer ring body 301. The outer ring body 301 forms a space to accommodate the next stage guide vane section, and the impeller 500 is also correspondingly installed in the inner area of ​​the outer ring body 301. The outer ring body 301 of the final-stage guide vane 320 is provided with multiple sets of outlets 321 evenly spaced along the circumference to output the liquid flow after the final multi-stage pressurization to the high-pressure zone of the pump body and finally discharge it through the outlet. Unlike the intermediate guide vane 310 and the final stage guide vane 320, the first stage guide vane 300 does not have a front guide vane section, but only an outer ring section 301. The guide vane section of the intermediate guide vane 310 is fitted into the outer ring section 301 of the first stage guide vane 300. The first stage impeller 500 is also installed in the outer ring section 301 of the first stage guide vane 300, and the guide vane section of the intermediate guide vane 310 is used for flow guidance. Similarly, the outer ring section 301 of the intermediate guide vane 310 is guided by the guide vane section of the final stage guide vane 320 until the liquid is guided into the final stage guide vane 320, thrown out by the final stage impeller 500, and directly discharged through the outlet 321 on the final stage guide vane 320. This achieves pressurization of the multi-stage impeller 500 to increase the head.

[0046] In this embodiment, the guide vane assemblies at each stage are sequentially abutted and positioned, and are pressed together between the front end cover of the pump housing 200 and the front bearing seat 400. More precisely, in this embodiment, the pre-selected specific design is that the tail end of the outer ring body 301 of each stage guide vane assembly is bent inward radially to form a second bend 305. The outer wall surface of the second bend 305 has a flat portion, and it contacts and abuts against the wall surface of the front bearing seat 400 through this flat portion. The front end of the outer ring body 301 is bent inward to form a first bend 302, and is connected to the assembly ring 303 through the first bend 302. The front end of the assembly ring 303 has a front end cover 304, and the guide vanes on the guide vane assembly are installed in front of the front end cover 304. The front end cover 304 is provided with a through hole for the pump shaft 102 to pass through. The first bend 302 extends at an angle, specifically inclining radially from the outside to the inside towards the tail end of the outer ring body 301. Furthermore, an arc-shaped transition portion is formed between the first bend 302 and the outer ring body 301, and this arc-shaped transition portion abuts against the flat portion of the second bend 305 on the preceding guide vane assembly for positioning. That is, the front end of the outer ring body 301 has an arc-shaped transition portion, and the rear end has a flat portion. During multi-stage assembly, the assembly ring portion 303 of the next stage guide vane assembly is correspondingly embedded in the second bend 305 of the preceding stage guide vane assembly, and the arc-shaped transition portion on the first bend 302 abuts against the flat portion on the second bend 305 of the preceding stage. For the first stage guide vane 300, the arc-shaped transition portion on the first bend 302 abuts against the flat surface of the inner wall of the pump casing 200; for the last stage guide vane 320, the flat portion on the second bend 305 abuts against the wall surface of the front bearing seat 400, thus realizing the step-by-step abutment positioning installation of the multi-stage guide vane assembly. Furthermore, the surface roughness of the upper plane of the bent portion 305 is preferably less than 3.2, and the perpendicularity of this plane reaches grade 7-9, with the flatness grade being lower than the perpendicularity grade. For example, the flatness is grade 7 and the perpendicularity is grade 8 or 9, to ensure that when the final stage guide vane 320 is installed, this plane maintains a tight abutment and positioning with the side wall plane of the front bearing housing 400, and has strong sealing performance, reducing leakage loss.

[0047] By employing the above-described method in this embodiment, a contact positioning method using a planar portion and an arc-shaped transition portion is used between each stage of the guide vane assembly. This achieves a surface-to-line contact positioning method, which effectively reduces the requirements for the flatness of the planar portion of the contact area and the parallelism requirements for the planar portion of the second bend 305 relative to the arc-shaped transition portion on the first bend 302. Furthermore, this contact method has a stronger self-adjusting function. The line contact between the arc-shaped transition portion of the first bend 302 and the planar portion of the second bend 305 allows for slight elastic deformation of the material near the contact area, forming an "elastic line contact." By coordinating local unevenness through deformation, a continuous sealing line can be formed, increasing the sealing performance between each stage of the guide vane assembly, reducing interstage leakage losses, and improving hydraulic efficiency. This line contact positioning method also avoids the flatness errors present in traditional surface contact methods, especially the cumulative errors between multiple stages of guide vane assemblies, which can lead to positioning tilting, poor coaxiality with the pump shaft 102, pump vibration and abnormal noise, or even malfunction. This linear contact can further distribute stress evenly along the contact line, avoiding stress concentration that could cause deformation of the contact surface and affect positioning accuracy.

[0048] Preferably, in practice, the bottom end of the second bend 305 continues to bend axially towards the first bend 302, forming an axially extending inner stop ring 306. An arc-shaped transition portion is formed between the inner stop ring 306 and the second bend 305. When assembling the multi-stage guide vane assembly, the second bend 305 and the inner stop ring 306 of the previous stage, together with the first bend 302 and the assembly ring 303 of the subsequent stage, form a variable diameter sealing area with a cross-section approaching a triangle. That is, the space increases radially inward, providing adequate space for the sealing ring installation. When the two stages of the guide vane assembly are in line contact and positioned, they can effectively compress the sealing ring, further improving the sealing performance between the guide vane assemblies, further reducing the head and efficiency losses caused by inter-stage leakage, and improving the pump's energy efficiency rating. In practice, the assembly ring 303 of the next-stage guide vane assembly corresponds to the inner stop ring 306 of the previous-stage guide vane assembly, and maintains a coaxial clearance fit. In practice, the radial fit clearance is preferably 0.02-0.2mm. The inner stop ring 306 of the previous-stage guide vane assembly forms a radial positioning for the next-stage guide vane assembly, which not only ensures the accuracy of positioning and installation, but also avoids the situation where double positioning cannot be installed. At the same time, it also reserves sufficient adjustment space for linear contact and can reduce the amount of fluid leakage from the high-pressure area to the low-pressure area in the guide vane, thereby improving the head and efficiency.

[0049] The guide vane portion of the guide vane assembly in this embodiment will be further described below. Preferred designs can be found by referring to... Figure 6 and Figure 7As shown, the impeller includes a forward guide vane 312 and a reverse guide vane 311 arranged sequentially along the water flow direction. The water flows through the forward guide vane 312, enters the reverse guide vane 311, and then enters the next stage impeller 500. The reverse guide vane 311 is fixed on the front end cover 304. The front end of the reverse guide vane 311 is connected to the forward guide vane 312 through the rear connecting wall 316. The front end of the forward guide vane 312 is provided with a radially extending front connecting wall 313, and the outer edge of the front connecting wall 313 is provided with an axially extending shaft extension ring 314. When the multi-stage guide vane assembly is assembled, the shaft extension ring 314 of the subsequent stage guide vane assembly and the inner wall of the assembly ring portion 303 of the previous stage guide vane assembly maintain an inner and outer coaxial clearance fit, specifically a radial clearance of 0.02-0.2 mm. Furthermore, the front end of the shaft extension ring 314 is provided with a radially inwardly extending radial extension ring 315. The radial extension ring 315 of the next stage guide vane assembly maintains a clearance fit with the inner wall of the front end cover 304 of the previous stage guide vane assembly. Specifically, the axial clearance is a fit clearance ≥ 0.5 mm, to ensure that the shaft extension ring 314 does not contact the front end cover 304 of the previous stage guide vane assembly, and to avoid the situation of double positioning at both ends of the same stage guide vane assembly affecting installation.

[0050] It should be noted that in the industry, after pressurization by multiple impellers 500, the liquid ejected by the final stage impeller 500 is often directly discharged through the outlet 321 within the final stage guide vane 320. However, the applicant has found that although there is multi-stage pressurization, if the liquid is directly discharged through the outlet 321 using the impeller 500 pressure within the final stage guide vane 320, there will still be some liquid turbulence and energy loss, resulting in inefficient liquid discharge. Therefore, in this embodiment, a front guide vane 330 is coaxially added inside the final stage guide vane 320, combined with... Figure 3 and Figure 5 As shown, the front guide vane 330 is surrounded by multiple sets of positive guide vanes 312 in the middle part corresponding to the impeller 500, which are used to guide the liquid thrown out by the impeller 500 to the outlet 321; the front end of the front guide vane 330 and the inner wall of the last stage guide vane 320 are positioned with clearance fit in both the axial and radial directions, and the tail end of the front guide vane 330 is fixedly connected to the front bearing seat 400.

[0051] More precisely, the leading vane section 330 is the front guide vane section structure of the guide vane assembly. The difference is that it only needs to be equipped with a positive guide vane 312, without the need for a negative guide vane 311. That is, the leading vane section 330 also has a positive guide vane 312 surrounding the outer periphery of the last-stage impeller 500. The end of the positive guide vane 312 still has a radially extending rear connecting wall 316, and the front end of the positive guide vane 312 still has a radially extending front connecting wall 313. The positive guide vane 312 is sandwiched between the front connecting wall 313 and the rear connecting wall 316. The front connecting wall 313 is also provided with a shaft extension ring 314 and a radial extension ring 315. The shaft extension ring 314 of the leading vane section 330 corresponds to the inner wall of the mounting ring section 303 of the last-stage guide vane 320, and maintains a radial clearance fit of 0.02-0.2 mm. The radial extension ring 315 of the leading vane 330 and the front end cover 304 of the final stage guide vane 320 maintain an axial clearance fit of ≥0.5mm.

[0052] This embodiment, by adding a front guide vane 330 within the final stage guide vane 320, can further achieve effective flow regulation of the pressurized liquid, ensure its outflow efficiency, reduce water pressure loss, and improve the pump's head performance. However, given the abutment installation method of each stage guide vane assembly, the applicant found in practice that it is difficult to effectively position the front guide vane 330. The final stage guide vane 320 needs to be abutted against the front bearing housing 400 and the previous stage intermediate guide vane 310. If the final stage guide vane 320 is used to abut against the front guide vane 330, it is easy to cause a double positioning of the final stage guide vane 320, making it impossible to match and install. On the other hand, maintaining a clearance fit between the front guide vane 330 and the final stage guide vane 320 will result in the front guide vane 330 wobbling, reduced coaxiality, easy vibration and abnormal noise, or even failure to operate. Based on this, the applicant further adjusted and optimized the connection, fixing the tail end of the guide vane 330 to the front bearing housing 400, such as by using fastening bolts 331, etc. Specifically, in combination with Figure 9 and Figure 10 As shown, the tail end of the leading guide vane 330 is provided with a fixed wall 318 that fits against the wall surface of the front bearing housing 400, and multiple sets of fastening bolts 331 are arranged around the fixed wall 318 to fix it to the front bearing housing 400. In this way, the front bearing housing 400 is used to effectively position the leading guide vane 330, which not only achieves clearance fit installation between the leading guide vane 330 and the last stage guide vane 320, ensuring the assembly and sealing effect of each stage guide vane assembly, but also ensures the positional stability of the leading guide vane 330 and reduces vibration and abnormal noise.

[0053] Furthermore, the following section elaborates on the specific structure of the front bearing housing 400. Figure 3 , Figure 4 , Figure 9 and Figure 10As shown, the front bearing housing 400 includes an inner main body 401. A shaft hole 402 is provided in the middle of the inner main body 401 for mounting the pump shaft 102. An axially extending third protruding ring 403 is provided on the wall surface of the inner main body 401 facing the front guide vane 330. A protrusion 317, correspondingly fitted into the third protruding ring 403, is provided at the tail end of the front guide vane 330 along the axial direction. A radially extending fixing wall 318 is provided at the tail end of the protrusion 317 and is fixedly connected to the inner main body 401. Specifically, the rear connecting wall 316 of the front guide vane 330 has an axially rearwardly extending protrusion 317, forming an L-shaped stop between the rear connecting wall 316 and the protrusion 317, which positions and engages with the third protruding ring 403. Secondly, the tail end of the bent portion 305 on the final stage guide vane 320 is also axially folded inward to form an inner stop ring 306. On the inner main body portion 401 of the front bearing housing 400, an axially protruding second convex ring portion 404 is also provided on the outer periphery of the third convex ring portion 403. The second convex ring portion 404 extends into the inner stop ring 306 and maintains a radial clearance fit of 0.02-0.2 mm. Furthermore, to achieve effective installation of the front bearing housing 400 between the base 100 and the pump casing 200, a third convex ring portion 406 is also provided on the front bearing housing 400 on the outer periphery of the second convex ring portion 404. The outer side of the third convex ring portion 406 is the outer edge portion 407 of the front bearing housing 400, and the outer main body portion 405 is formed between the second convex ring portion 404 and the third convex ring portion 406. The pump housing 200 is fitted onto the base 100 by the outer periphery of the third convex ring 406 and the outer edge 407, and a sealing ring is provided between the pump housing 200 and the third convex ring 406 to further prevent leakage.

[0054] This embodiment can further improve the hydraulic performance of the pump body by adding a front guide vane 330. By making a clearance fit between the front end of the front guide vane 330 and the last stage guide vane 320, and fixing the tail end to the front bearing seat 400 by fastening bolts 331, the precise matching and positioning installation of each stage guide vane assembly and the stable installation of the front guide vane 330 itself are ensured, thus fully guaranteeing the pump body performance.

[0055] The scope of protection of this utility model is defined only by the claims. Thanks to the teachings of this utility model, those skilled in the art will readily recognize that alternative structures to the disclosed structure can be used as feasible alternative implementations, and that the disclosed implementations can be combined to produce new implementations, which also fall within the scope of the appended claims.

Claims

1. A high-lift multistage impeller pump, comprising a base (100), a pump casing (200), and a front bearing housing (400) pressed between the base (100) and the pump casing (200), wherein a multistage set of cooperating impellers (500) and guide vane assemblies are arranged around the outer periphery of the pump shaft (102) within the pump casing (200), characterized in that: The multi-stage guide vane assembly includes at least a final stage guide vane (320), and multiple sets of outlets (321) are provided on the outer peripheral wall of the final stage guide vane (320) at positions corresponding to the final stage impeller (500); the axial tail end of the final stage guide vane (320) is positioned against the front bearing housing (400), and the axial front end of the final stage guide vane (320) is positioned against the previous stage guide vane assembly; The final stage guide vane (320) has a coaxially arranged front guide vane (330). The front guide vane (330) is surrounded by multiple sets of positive guide vanes (312) in the middle corresponding to the impeller (500) to guide the liquid thrown out by the impeller (500) to the outlet (321). The front end of the front guide vane (330) and the inner wall of the final stage guide vane (320) are positioned with clearance fit in both the axial and radial directions. The tail end of the front guide vane (330) is fixedly connected to the front bearing housing (400).

2. The high-lift multistage impeller pump according to claim 1, characterized in that: The axial clearance between the front end of the guide vane (330) and the inner wall of the final guide vane (320) is ≥0.5mm, and the radial clearance is 0.02-0.2mm.

3. A high-lift multistage impeller pump according to claim 1, characterized in that: The tail end of the front guide vane (330) is provided with a fixed wall (318) that fits against the wall of the front bearing housing (400), and multiple sets of fastening bolts (331) are arranged around the fixed wall (318) to fix it to the front bearing housing (400).

4. A high-lift multistage impeller pump according to any one of claims 1-3, characterized in that: The front bearing housing (400) includes an inner body (401), and a shaft hole (402) is provided in the middle of the inner body (401) for mounting the pump shaft (102). The inner body (401) has an axially extending third protruding ring (403) on the wall surface facing the front guide vane (330). The tail end of the front guide vane (330) is provided with a protrusion (317) that fits into the third protruding ring (403) in the axial direction. The tail end of the protrusion (317) is provided with a radially extending fixed wall (318) that is fixedly connected to the inner body (401).

5. A high-lift multistage impeller pump according to claim 4, characterized in that: The final stage guide vane (320) includes an outer ring body (301), within which an installation space is formed for an impeller (500) and a front guide vane (330), and an outlet (321) is opened on the outer ring body (301); the front end of the outer ring body (301) has a guide vane that extends into the outer ring body (301) of the previous stage guide vane assembly and cooperates with the previous stage impeller (500); the tail end of the outer ring body (301) is bent inward to form a second bend (305), the outer wall of the second bend (305) has a flat portion, and the flat portion contacts and abuts against the wall of the front bearing housing (400) for positioning.

6. A high-lift multistage impeller pump according to claim 5, characterized in that: The roughness of the upper flat surface of the bending part (305) is less than 3.2, and the perpendicularity of the flat surface reaches level 7-9, which is lower than the perpendicularity level.

7. A high-lift multistage impeller pump according to claim 5, characterized in that: The front end of the outer ring body (301) is bent inward to form a bending part one (302), and is connected to the assembly ring part (303) through the bending part one (302). The front end of the assembly ring part (303) has a front end cover (304), and the guide vanes on the guide vane assembly are installed in front of the front end cover (304). An arc-shaped transition part is formed between the bending part one (302) and the outer ring body (301), and the arc-shaped transition part abuts against the flat part of the bending part two (305) on the front guide vane assembly for positioning.

8. A high-lift multistage impeller pump according to claim 7, characterized in that: The leading vane (330) has an axially extending ring (314) in front of the leading vane (312). The axial extending ring (314) corresponds to the inner wall of the mounting ring (303) of the last stage guide vane (320) and maintains a radial clearance fit.

9. A high-lift multistage impeller pump according to claim 8, characterized in that: The front end of the shaft extension ring (314) is bent inward to form a radial extension ring (315), and the radial extension ring (315) maintains an axial clearance fit with the front end cover (304) of the last stage guide vane (320).

10. A high-lift multistage impeller pump according to claim 5, characterized in that: The tail end of the second bending part (305) is folded inward along the axial direction to form an inner stop ring (306). The inner main body part (401) of the front bearing housing (400) is also provided with an axially protruding second convex ring part (404) on the outer periphery of the third convex ring part (403). The second convex ring part (404) extends into the inner stop ring (306) and maintains a radial clearance fit.

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