A main shaft for a vertical mixed flow pump

Abstract

The utility model discloses a main shaft for vertical mixed flow pump, including at least two main shaft sections of connecting in proper order, each main shaft section coaxial connection in proper order, be equipped with two interval arrangement's coaxial's reference section of cylinder on each main shaft section, and the reference section is the reference of the main shaft section processing and overhauling, when the main shaft is installed on the mixed flow pump, does not install and cooperate any component on the reference section. The utility model designs the reference section of overhauling at two ends of each main shaft section, provides the processing reference for other function sections when manufacturing, is used for the main shaft bending detection reference when overhauling, avoids the detection error because of the main shaft wear.

Description

Technical Field

[0001] This utility model belongs to the technical field of mixed flow pump spindles, specifically a spindle for a vertical mixed flow pump. Background Technology

[0002] Mixed-flow pumps are characterized by their small footprint, wide efficiency range, stable structure, long maintenance intervals, convenient maintenance, and stable power output within their operating range. They are widely used in circulating water pumps in thermal power plants, nuclear power plants, petrochemical industries, and water plants. The main shaft, as a crucial component for transmitting torque in mixed-flow pumps, directly determines the pump's operational stability and overhaul cycle. The normal overhaul period for mixed-flow pumps is 4-6 years. Currently, the conventional mixed-flow pump main shaft structure uses the coupling or impeller mating section as the reference section for inspection or straightening during maintenance. However, during operation, because this shaft section is a clearance fit surface, after an overhaul, this reference section is often worn or corroded and can no longer be used as a reference. Continuing to use it as an inspection reference can lead to misjudgments of the main shaft's bending condition, resulting in safety hazards or excessive maintenance and increased costs. Utility Model Content

[0003] To address the aforementioned problems in the existing technology, the purpose of this utility model is to provide a spindle for a vertical mixed-flow pump, wherein each spindle section is designed with maintenance reference sections at both ends, which provide machining references for other functional sections during manufacturing and serve as a reference for spindle bending detection during overhaul, thereby avoiding detection errors caused by spindle wear.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0005] A spindle for a vertical mixed-flow pump includes at least two spindle sections connected in sequence, each spindle section being coaxially connected in sequence. Each spindle section is provided with two coaxial reference sections arranged at intervals. The reference sections serve as the reference for machining and maintenance of the spindle sections. When the spindle is installed on the mixed-flow pump, no components are installed or fitted on the reference sections.

[0006] As a further improvement to the above technical solution:

[0007] Each spindle section also has at least three neutral sections. The two sections adjacent to each reference section are neutral sections. No parts are installed on the neutral sections, and the outer diameter of the neutral section is smaller than the outer diameter of the reference section.

[0008] The difference between the outer diameter of the reference section and the outer diameter of the neutral section is 1mm to 30mm.

[0009] Each spindle section also includes a bushing section and a coupling section. The bushing section is used to install the bushing, and the coupling section is used to install the coupling.

[0010] Two adjacent main shaft sections are connected by a coupling. One end of the main shaft is connected to a drive motor via the coupling, and the other end is connected to the impeller of the mixed flow pump. After the drive motor starts, it transmits torque to the impeller through the main shaft, causing the impeller to rotate.

[0011] It has three main shaft sections, namely the upper main shaft, the middle main shaft and the lower main shaft connected from top to bottom. The coupling connecting two adjacent main shaft sections is a sleeve coupling. The upper end of the upper main shaft is connected to the drive motor through the pump coupling, and the lower end of the lower main shaft is connected to the impeller.

[0012] The main spindle includes a bushing section, two coupling sections, two reference sections, two retaining ring sections, and four neutral sections. The two coupling sections are the first coupling section and the second coupling section, the two reference sections are the first reference section and the second reference section, the two retaining ring sections are the first retaining ring section and the second retaining ring section, and the four neutral sections are the first neutral section, the second neutral section, the third neutral section, and the fourth neutral section. The first coupling section, the first retaining ring section, the first neutral section, the first reference section, the second neutral section, the second reference section, the third neutral section, the bushing section, the fourth neutral section, the second retaining ring section, and the second coupling section are coaxially connected from bottom to top along the axial direction of the main spindle.

[0013] The outer diameters of the retaining ring section, coupling section, neutral section, and reference section increase sequentially.

[0014] At least one end of the upper spindle bushing section is provided with external threads for installing the bushing nut.

[0015] Each spindle segment can be coupled with two support members. The two support members are placed on the ground or on a workbench, and the spindle segment is horizontally supported on the two support members. The two reference segments of the spindle segment are respectively in contact with and supported on the two support members. Other parts of the spindle segment do not contact the support members. When the spindle segment is supported on the two support members, it can rotate under the drive of external force.

[0016] The beneficial effects of this utility model are:

[0017] (1) Provide a reliable inspection benchmark: By setting up maintenance benchmark sections at both ends of the spindle that do not cooperate with any parts, it is ensured that the section always maintains the initial machining accuracy and is free from wear throughout the entire pump operation cycle. During overhaul, using this as an inspection benchmark can truly and accurately reflect the actual form and position tolerances and bending conditions of each functional section of the spindle.

[0018] (2) Improve machining accuracy: During the manufacturing process, all key functional sections (sleeve section, retaining ring section, coupling section, etc.) are machined based on the same pair of maintenance reference sections, ensuring high coaxiality between sections, thereby improving the overall manufacturing quality and dynamic balance performance of the spindle.

[0019] (3) Avoid maintenance risks: It effectively eliminates the risk of "defect omission" or "qualification misjudgment" that may be caused by the wear of the reference, which not only ensures the safe operation of the unit, but also avoids unnecessary maintenance costs and waste of resources.

[0020] (4) The overall structure is simple and the cost is low. Attached Figure Description

[0021] Figure 1 This is a structural schematic diagram of one embodiment of the present invention.

[0022] Figure 2 This is a cross-sectional structural diagram of one embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of the spindle structure in one embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram of the main shaft section and its cooperation with the support components during maintenance, according to one embodiment of this utility model. Detailed Implementation

[0025] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.

[0026] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0027] A spindle for a vertical mixed-flow pump, such as Figures 1-4 As shown, the system includes at least two main shaft sections connected in sequence, and at least two couplings. Adjacent main shaft sections are connected by a coupling. One end of each main shaft is connected to a drive motor via a coupling, and the other end is connected to the impeller 400 of the mixed-flow pump. After the drive motor starts, it transmits torque to the impeller 400 through the main shaft, causing the impeller 400 to rotate.

[0028] In this embodiment, three main shaft sections are provided: an upper main shaft 100, a middle main shaft 200, and a lower main shaft 300 connected sequentially from top to bottom. A sleeve coupling 600 connects adjacent main shaft sections. The upper end of the upper main shaft 100 is connected to a drive motor (not shown in the figure) via a pump coupling 500, and the lower end of the lower main shaft 300 is connected to an impeller 400. The impeller 400 is engaged with the lower main shaft 300 and secured with bolts. The connection between the impeller 400 and the lower main shaft 300 is existing technology and will not be described further here.

[0029] The upper spindle 100, middle spindle 200 and lower spindle 300 have similar structures. The following explanation will take the middle spindle 200 as an example.

[0030] 200mm spindle Figure 3 and 4 As shown, the structure includes a cylindrical bushing section 8, two coupling sections, two reference sections, two retaining ring sections, and four neutral sections. The two coupling sections are designated as first coupling section 1 and second coupling section 11; the two reference sections are designated as first reference section 4 and second reference section 6; the two retaining ring sections are designated as first retaining ring section 2 and second retaining ring section 10; and the four neutral sections are designated as first neutral section 3, second neutral section 5, third neutral section 7, and fourth neutral section 9. The first coupling section 1, first retaining ring section 2, first neutral section 3, first reference section 4, second neutral section 5, second reference section 6, third neutral section 7, bushing section 8, fourth neutral section 9, second retaining ring section 10, and second coupling section 11 are coaxially connected from bottom to top along the main shaft axis.

[0031] The reference section serves as the machining reference for the main spindle. Two coupling sections are used to install couplings. The first coupling section 1 and the lower main spindle 300 are coaxially connected via a sleeve coupling 600, and the second coupling section 11 and the upper main spindle 100 are coaxially connected via another sleeve coupling 600. The bushing section 8 is used to install the bushing 800, which is positioned by a key. A guide bearing will be fitted onto the bushing 800. The retaining ring section is used to install the retaining ring 700, which is used for axial positioning and limiting of the sleeve coupling 600. The retaining ring 700 is a split retaining ring; after being inserted into the retaining ring section, it is connected to the sleeve coupling 600 via screws for axial positioning. No parts are installed on the reference section and the neutral section; that is, the reference section does not contact or engage with any parts to avoid wear on the reference section.

[0032] The outer diameters of all neutral sections, coupling sections, reference sections, and retaining ring sections are equal. The outer diameters of the retaining ring sections, coupling sections, neutral sections, and reference sections increase sequentially. The outer diameter of bushing section 8 is equal to that of the reference section.

[0033] The difference between the outer diameter of the reference section and the outer diameter of the neutral section is 1mm to 30mm.

[0034] In this embodiment, the outer diameter of the reference section of different spindle segments is equal.

[0035] In this embodiment, the outer diameter of the reference section is 225mm, the outer diameter of the neutral section is 224mm, the outer diameter of the coupling section is 220mm, and the outer diameter of the retaining ring section is 204.9mm.

[0036] In this embodiment, the lengths of the two reference sections are equal, the lengths of the two coupling sections are equal, the lengths of the two retaining ring sections are equal, and the lengths of the first neutral section 3 and the third neutral section 7 are equal. In this embodiment, the lengths of the second neutral section 5 and the fourth neutral section 9 are greater than the length of the first neutral section 3.

[0037] As shown above, this is equivalent to two reference segments being spaced apart at the upper and lower ends of the main shaft segment.

[0038] The upper spindle 100, lower spindle 300 and middle spindle 200 have similar structures, both with two spaced reference sections. The difference is that other functional sections can be flexibly adjusted according to specific needs.

[0039] In this embodiment, for the upper spindle 100, at least one end of the upper spindle 100 bushing section is provided with an external thread to install the bushing nut 900. The bushing nut 900 is used to position and limit the bushing 800 on the upper spindle 100.

[0040] Based on the above structure, when machining the main spindle section, the two reference sections at both ends of the main spindle section are machined first. After the main spindle is centered, the reference sections are used as a unified positioning and measurement reference to machine the bushing section 8, each retaining ring section, each coupling section, etc.

[0041] In this embodiment, the two reference sections are selected with a coaxiality tolerance of grade 8 and a surface roughness Ra of 0.8 μm. The bushing section 8 is selected with a runout tolerance of grade 7 and a surface roughness Ra of 0.8 μm. The retaining ring section is selected with a runout tolerance of grade 8 and a perpendicularity tolerance of grade 6, and a surface roughness Ra of 3.2 μm. The coupling section is selected with a runout tolerance of grade 7 and a surface roughness Ra of 0.8 μm. The form and position tolerances of the gap section comply with the K-grade tolerance requirements in GB / T 1184-1996.

[0042] The system also includes two support members 12 that cooperate with the spindle. When the spindle needs maintenance, the two support members 12 are placed on the ground or a workbench, and the spindle section is horizontally supported on the two support members 12. The two reference sections of the spindle section are respectively in contact with and supported on the two support members 12, while other parts of the spindle section do not contact the support members 12. When the spindle section is supported on the two support members 12, it can rotate under external force.

[0043] In this embodiment, the support member 12 is precision machined and calibrated.

[0044] In this embodiment, the support member 12 is an inclined pad or a roller.

[0045] After the entire main shaft is assembled into the pump body, the two reference sections of each main shaft section are in an "idle" state, without contacting or engaging with bearings, seals, bushings or any other parts inside the pump, thus remaining clean and undamaged even after long-term operation.

[0046] Based on the above structure, when overhauling the main shaft, the main shaft is lifted out of the pump body, and the two reference sections of each main shaft segment are placed on two support members 12 respectively. The main shaft segment is rotated to check each of the remaining functional sections with a dial indicator, and the results are compared with the calculated standard shaft (e.g., the maximum radial runout is 0.083L, where L is at most 1 / 2 shaft length) to determine the bending condition of the main shaft. In other words, during overhaul, two reference sections are used as the reference for main shaft overhaul. The runout of the bushing section 8, the retaining ring section, the coupling section, the neutral section, etc., is checked with a dial indicator to correctly assess the bending degree of the main shaft. Because the reference sections at both ends of the main shaft do not participate in the contact or cooperation of other parts, the test reference (reference section) is intact, and the measured runout value truly reflects the deviation of each functional section relative to the theoretical axis of the main shaft, which can effectively avoid misjudgment of the main shaft bending during overhaul due to wear of the main shaft reference section.

[0047] Finally, it is necessary to state that the above embodiments are only used to further illustrate the technical solution of this utility model in detail, and should not be construed as limiting the scope of protection of this utility model. Any non-essential improvements and adjustments made by those skilled in the art based on the above content of this utility model shall fall within the scope of protection of this utility model.

Claims

1. A spindle for a vertical mixed-flow pump, characterized in that, It includes at least two main shaft sections connected in sequence, each main shaft section being coaxially connected in sequence. Each main shaft section is provided with two coaxial reference sections arranged at intervals. The reference sections serve as the reference for machining and maintenance of the main shaft sections. When the main shaft is installed on the mixed flow pump, no components are installed or fitted on the reference sections.

2. The spindle according to claim 1, characterized in that: Each spindle section also has at least three neutral sections. The two sections adjacent to each reference section are neutral sections. No parts are installed on the neutral sections, and the outer diameter of the neutral section is smaller than the outer diameter of the reference section.

3. The spindle according to claim 2, characterized in that: The difference between the outer diameter of the reference section and the outer diameter of the neutral section is 1mm to 30mm.

4. The spindle according to claim 2, characterized in that: Each spindle section also includes a bushing section (8) and a coupling section. The bushing section (8) is used to install the bushing (800), and the coupling section is used to install the coupling.

5. The spindle according to any one of claims 1 to 4, characterized in that: Two adjacent main shaft sections are connected by a coupling. One end of the main shaft is connected to a drive motor through the coupling, and the other end is connected to the impeller (400) of the mixed flow pump. After the drive motor starts, it transmits torque to the impeller (400) through the main shaft, causing the impeller (400) to rotate.

6. The spindle according to claim 5, characterized in that: There are three main shaft sections, namely the upper main shaft (100), the middle main shaft (200) and the lower main shaft (300) connected from top to bottom. The coupling connecting two adjacent main shaft sections is a sleeve coupling (600). The upper end of the upper main shaft (100) is connected to the drive motor through the pump coupling (500), and the lower end of the lower main shaft (300) is connected to the impeller (400).

7. The spindle according to claim 6, characterized in that: The main spindle (200) includes a bushing section (8), two coupling sections, two reference sections, two retaining ring sections, and four neutral sections. The two coupling sections are the first coupling section (1) and the second coupling section (11), the two reference sections are the first reference section (4) and the second reference section (6), the two retaining ring sections are the first retaining ring section (2) and the second retaining ring section (10), and the four neutral sections are the first neutral section (3), the second neutral section (5), the third neutral section (7), and the fourth neutral section (9). The first coupling section (1), the first retaining ring section (2), the first neutral section (3), the first reference section (4), the second neutral section (5), the second reference section (6), the third neutral section (7), the bushing section (8), the fourth neutral section (9), the second retaining ring section (10), and the second coupling section (11) are coaxially connected from bottom to top along the axial direction of the main spindle.

8. The spindle according to claim 7, characterized in that: The outer diameters of the retaining ring section, coupling section, neutral section, and reference section increase sequentially.

9. The spindle according to claim 6, characterized in that: At least one end of the upper spindle (100) bushing section is provided with external thread for installing bushing nut (900).

10. The spindle according to claim 6, characterized in that: Each spindle segment can be coupled with two support members (12). The two support members (12) are placed on the ground or on a workbench, and the spindle segment is horizontally supported on the two support members (12). The two reference segments of the spindle segment are respectively in contact with and supported on the two support members (12). Other parts of the spindle segment are not in contact with the support members (12). When the spindle segment is supported on the two support members (12), it can rotate under the drive of external force.

Images