Efficient adjustment system for tip clearance of semi-open impeller of sewage pump

Abstract

The present application relates to a kind of sewage pumps semi-open impeller tip clearance high-efficiency adjustment system, the system includes pump body, impeller, suction cover, insert ring, clearance measuring device, axial adjusting device, displacement monitoring device, wherein clearance measuring device is used to directly obtain the tip clearance value of the impeller outlet side;Axial adjusting device connects suction cover and insert ring, for driving the insert ring along the axial movement of the suction cover outside the pump body;Displacement monitoring device is used to monitor the axial displacement of insert ring in real time and output feedback signal;The feedback signal of displacement monitoring device is used to indicate the real-time displacement of insert ring under the driving of axial adjusting device, to compare with the target displacement amount calculated based on the measurement result of clearance measuring device, to complete the adjustment of tip clearance.The present application realizes a kind of adjustment structure of external operation, real-time feedback;Provide a kind of high-efficiency adjustment system capable of realizing the coordinated optimization of impeller inlet side, outlet side tip clearance.

Description

Technical Field

[0001] This invention relates to an efficient impeller tip clearance adjustment system, specifically to an efficient adjustment system for the tip clearance of a semi-open impeller of a sewage pump that integrates precise measurement, external adjustment, and displacement feedback. Background Technology

[0002] Semi-open impeller submersible sewage pumps are widely used in building drainage, municipal sewage treatment, and industrial wastewater treatment due to their excellent non-clogging performance.

[0003] The core contradiction between the performance and operational reliability of this semi-open impeller lies in the critical parameter of the tip clearance. From a fluid dynamics perspective, this clearance needs to be minimized to reduce leakage losses and improve efficiency. However, from a safe operation perspective, this clearance needs to be large enough to prevent the impeller from rubbing against other parts and jamming. Therefore, how to achieve convenient and accurate measurement, adjustment, and maintenance of the tip clearance, and keep it at its optimal value over the long term, is a technical challenge that has troubled those skilled in the art.

[0004] Figure 1 The adjustment structure for the semi-open impeller tip clearance of a submersible sewage pump mainly includes a pump body 1', impeller 2', suction cover 3', insertion ring 4', screw 10', and adjusting screw 9'. The suction cover 3' is fixed to the pump body 1' by screws, and the insertion ring 4' and suction cover 3' are connected by screw 10'. To adjust the clearance, first use a feeler gauge to measure the impeller inlet side blade tip clearance, i.e., the clearance between the impeller inlet side blades and the insertion ring. Subtract the design value from the measured clearance to calculate the corresponding clearance adjustment amount. Then, remove the suction cover, loosen the screw between the insertion ring and the suction cover, and adjust the relative distance between the insertion ring and the suction cover by turning the adjusting screw the corresponding number of turns according to the clearance adjustment amount. Then, tighten the screw between the insertion ring and the suction cover. Finally, reinstall the suction cover and remeasure the impeller inlet side blade tip clearance with a feeler gauge. If the measured clearance does not meet the design value, the above operation needs to be repeated for adjustment.

[0005] from Figure 1 It can be seen that the existing solution has two major flaws.

[0006] First, after each adjustment, reassembly is required to verify the results; if they do not meet the requirements, disassembly and restarting are necessary. This prevents continuous, real-time, and precise adjustments, resulting in low adjustment accuracy and maintenance efficiency, and placing high demands on the skills and experience of operators.

[0007] Second, this scheme lacks the ability to directly measure the impeller outlet-side blade tip clearance, resulting in a measurement blind spot. The scheme can only measure the impeller inlet-side blade tip clearance and assumes that the impeller outlet-side blade tip clearance changes by the same amount. However, due to manufacturing deviations, uneven wear, and other factors, the changes in these two clearances are not directly related. This leads to a lack of a true value for the outlet-side blade tip clearance during adjustment, requiring a rough judgment based on the resistance felt when manually rotating the impeller after adjustment. This is a non-quantitative and highly subjective indirect judgment method, which is the root cause of the pump's inability to achieve optimal efficiency and the potential risk of friction. Summary of the Invention

[0008] To address the aforementioned problems, the main objective of this invention is to provide a high-efficiency adjustment system for the tip clearance of a semi-open impeller in a sewage pump, integrating precise measurement, external adjustment, and displacement feedback.

[0009] This invention solves the above-mentioned technical problems through the following technical solution: a high-efficiency adjustment system for the tip clearance of a semi-open impeller of a sewage pump, the system comprising a pump body, an impeller, a suction cover, and an insertion ring, and further comprising: A clearance measuring device is used to directly obtain the blade tip clearance value on the outlet side of the impeller.

[0010] An axial adjustment device, connecting the suction cover and the insertion ring, is used to drive the insertion ring to move axially along the suction cover from outside the pump body.

[0011] A displacement monitoring device is used to monitor the axial displacement of the insertion ring in real time and output a feedback signal.

[0012] The feedback signal from the displacement monitoring device is used to indicate the real-time displacement of the insert ring driven by the axial adjustment device, and to compare it with the target displacement calculated based on the measurement results of the gap measuring device, thereby completing the adjustment of the blade tip clearance.

[0013] In a specific embodiment of the present invention, the gap measuring device includes a first observation hole and a second observation hole formed on the pump body and communicating with the pump cavity. The center lines of the first observation hole and the second observation hole intersect in the region where the blade tip gap is located on the impeller outlet side.

[0014] In a specific embodiment of the present invention, the axial adjustment device includes at least three adjusting screws, the threaded portion of the adjusting screws being threadedly connected to the insertion ring, the smooth portion of the adjusting screws passing through the light hole on the suction cover and being fixed to the outside of the suction cover by a locking component.

[0015] In a specific embodiment of the present invention, the displacement monitoring device is a magnetostrictive displacement sensor, the waveguide of the magnetostrictive displacement sensor is fixed inside the suction cover, and a magnetic ring corresponding to the waveguide is fixed on the insertion ring.

[0016] In a specific embodiment of the present invention, both the first observation hole and the second observation hole are threaded holes and are equipped with sealing plugs; the angle θ between the centerline of the first observation hole and the second observation hole and the centerline of the pump shaft is 55° to 90°, the angle γ between the centerlines of the first observation hole and the second observation hole is 60° to 90°, and the angle ε between the symmetrical centerline of the first observation hole and the second observation hole and the vertical axis is 30° to 60°.

[0017] In a specific embodiment of the present invention, a waterproof magnetostrictive displacement sensor is provided on the suction cap, and a magnetic ring is provided at a corresponding position at the rear end of the insertion ring. The magnetic ring is fixed to the insertion ring with a demagnetizing screw. When the insertion ring moves axially, the magnetic ring moves accordingly. The waveguide of the magnetostrictive displacement sensor is built-in, and a waveguide mounting hole is provided at the rear end of the insertion ring.

[0018] In a specific embodiment of the present invention, a limiting ring located between the suction cover and the insertion ring is also included to limit the maximum axial movement stroke of the insertion ring. At least one scraping groove is provided on the end face of the insertion ring opposite to the impeller.

[0019] In a specific embodiment of the present invention, the limiting ring is designed as a fan-shaped annular structure, and fan-shaped annular grooves E and F are machined on the insertion ring and the suction cover; after the suction cover and the insertion ring are assembled, the limiting ring is placed in the groove; an annular groove D is provided on the limiting ring, and screws are installed through the annular groove D to fix the limiting ring to the suction cover; the central angle β of the limiting ring is designed to be 60° to 90°, and to facilitate the installation of the limiting ring, the central angle α of the fan-shaped annular groove on the suction cover and the insertion ring is 2° to 3° larger than the central angle β of the limiting ring.

[0020] A method for adjusting the blade tip clearance using the above-mentioned adjustment system includes the following steps: measuring the first blade tip clearance δ1 on the inlet side and the second blade tip clearance δ0 on the outlet side of the impeller; determining the required axial displacement adjustment amount Δδ of the insert ring based on the deviations of δ1 and δ0 from the design target values; operating the axial adjustment device under the real-time signal guidance of the displacement monitoring device to move the insert ring by the axial displacement adjustment amount Δδ; re-measuring δ1 and δ0 to verify the adjustment result.

[0021] The displacement data output by the displacement monitoring device is continuously recorded; when the displacement data indicates that the insertion ring has moved close to the maximum stroke limited by the limiting ring, an insertion ring wear and replacement warning is generated.

[0022] The positive and progressive effects of this invention are as follows: The semi-open impeller tip clearance high-efficiency adjustment system for sewage pumps provided by this invention has the following advantages: 1. By introducing a displacement monitoring device, the process of repeatedly disassembling and adjusting based on experience is transformed into precise quantitative adjustment that can be completed in one go with visualized data. The time for a single adjustment can be shortened and the gap control accuracy can be significantly improved.

[0023] 2. The unique "dual-hole intersection measurement method" solves the technical problem that the tip clearance of the outlet side blade cannot be directly measured, so that the tip clearance of the impeller inlet and outlet side blades is optimized to the best value, ensuring the pump's operating efficiency and reliability, reducing the vibration risk caused by uneven clearance, and fundamentally eliminating the friction risk caused by the unknown tip clearance of the outlet side blade.

[0024] 3. By introducing an axial adjustment device, the axial movement of the insertion ring is directly driven from outside the pump, avoiding the tedious operation of repeated disassembly and assembly, reducing the risk of damage to parts caused by frequent disassembly and assembly, and lowering the experience and skill requirements for operators.

[0025] 4. All new functions (regulation, measurement, monitoring, and limit) are highly integrated into the original structure of the pump body without changing its external dimensions. Through precise mechanical design and multiple sealing designs, the long-term reliable operation of the regulation system in wastewater environments is guaranteed. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a commonly used structure.

[0027] Figure 2 This is a schematic diagram of the overall structure of the present invention.

[0028] Figure 3 for Figure 2 Enlarged view of point M.

[0029] Figure 4 for Figure 2 Enlarged view of point N.

[0030] Figure 5 This is a schematic diagram showing the location of the pump body observation hole in this invention.

[0031] Figure 6-1 This is a front view of the limiting ring in this invention.

[0032] Figure 6-2 This is a left view of the limiting ring in this invention.

[0033] Figure 7 This is a schematic diagram of the inhalation cap in this invention.

[0034] Figure 8 This is a schematic diagram of the insertion ring in this invention.

[0035] The following are the names corresponding to the reference numerals in this invention: Figure 1 In the middle: pump body 1', impeller 2', suction cover 3', insertion ring 4', adjusting screw 9', screw 10'.

[0036] Figures 2-8 In the middle section: Pump body 1, impeller 2, suction cover 3, insertion ring 4, first observation hole 5, second observation hole 6, sealing plug 7, waterproof magnetostrictive displacement sensor 8, first adjusting screw 9, magnetic ring 10, demagnetizing screw 11, limit ring 12, waveguide 13, scraper groove 14, adjusting screw 16, detachable nut protective sleeve 17, hard washer 18, first sealing ring 19, nut 20, second sealing ring 21, spring washer 22, boss 23; guide section 301, threaded part 1601, smooth rod part 1602, milled flat 1603, labyrinth seal 1201. Detailed Implementation

[0037] The preferred embodiments of the present invention are given below with reference to the accompanying drawings to illustrate the technical solution of the present invention in detail.

[0038] Figure 2 This is a schematic diagram of the overall structure of the present invention. Figure 3 for Figure 2 Enlarged view at point M, Figure 4 for Figure 2 Enlarged view at N points, such as Figures 2-4 As shown: The present invention proposes a high-efficiency adjustment system for the tip clearance of a semi-open impeller of a sewage pump. The high-efficiency adjustment system for the tip clearance of a semi-open impeller of a sewage pump includes a pump body 1, an impeller 2, a suction cover 3 and an insertion ring 4, and also includes a clearance measuring device, an axial adjustment device and a displacement monitoring device.

[0039] The clearance measuring device is used to directly obtain the blade tip clearance value on the impeller outlet side; the axial adjustment device connects the suction cover 3 and the insertion ring 4, and is used to drive the insertion ring 4 to move axially along the suction cover 3 from outside the pump body 1; the displacement monitoring device is used to monitor the axial displacement of the insertion ring 4 in real time and output a feedback signal.

[0040] The feedback signal from the displacement monitoring device is used to indicate the real-time displacement of the insertion ring 4 under the drive of the axial adjustment device, so as to compare it with the target displacement calculated based on the measurement results of the clearance measuring device, thereby completing the adjustment of the blade tip clearance.

[0041] The clearance measuring device includes a first observation hole 5 and a second observation hole 6 that are opened on the pump body and communicate with the pump cavity. The center lines of the first observation hole 5 and the second observation hole 6 intersect in the area where the blade tip clearance is located on the outlet side of the impeller 2.

[0042] The axial adjustment device includes at least three first adjusting screws 9, the threaded portion of which is threadedly connected to the insertion ring 4, and the smooth portion of which passes through the smooth hole on the suction cover 3 and is fixed to the outside of the suction cover 3 by a locking component.

[0043] The displacement monitoring device is a waterproof magnetostrictive displacement sensor 8. The waveguide 13 of the waterproof magnetostrictive displacement sensor is fixed inside the suction cover 3, and a magnetic ring 10 corresponding to the waveguide 13 is fixed on the insertion ring 4.

[0044] In the specific implementation process, the first observation hole 5 and the second observation hole 6 in this invention are both threaded holes and are equipped with sealing plugs 7; the angle θ between the center line of the first observation hole 5 and the second observation hole 6 and the center line of the pump shaft is 55° to 90°, the angle γ between the center lines of the first observation hole 5 and the second observation hole 6 is 60° to 90°, and the angle ε between the symmetrical center line of the first observation hole 5 and the second observation hole 6 and the vertical axis is 30° to 60°.

[0045] In specific implementation, this invention features a waterproof magnetostrictive displacement sensor 8 mounted on the suction cap 3, and a magnetic ring 10 positioned at a corresponding location at the rear end of the insertion ring 4. The magnetic ring 10 is fixed to the insertion ring 4 using a demagnetizing screw 11. When the insertion ring 4 moves axially, the magnetic ring 10 moves accordingly. The waveguide 13 of the waterproof magnetostrictive displacement sensor 8 is internally mounted, and a waveguide mounting hole is provided at the rear end of the insertion ring 4. The sensor size can be selected according to structural requirements.

[0046] In specific implementation, the present invention includes a limiting ring 12 located between the suction cap 3 and the insertion ring 4, which is used to limit the maximum axial movement of the insertion ring 4.

[0047] In the specific implementation process, at least one scraping groove 14 is provided on the end face of the insertion ring 4 opposite to the impeller 2.

[0048] In the specific implementation process, the limiting ring 12 of this invention is designed as a fan-shaped annular structure, with fan-shaped annular grooves E and F machined on the insertion ring and suction cover. After the suction cover and insertion ring are assembled, the limiting ring is placed into the groove. An annular groove D is provided on the limiting ring, and screws are installed through the annular groove D to fix the limiting ring 12 to the suction cover. The central angle β of the limiting ring is designed to be 60° to 90°, and the size of the screw holes on the limiting ring is selected according to the actual structure, with a quantity of 3 to 5. To facilitate the installation of the limiting ring 12, the central angle α of the fan-shaped annular grooves on the suction cover 3 and insertion ring 4 is 2° to 3° larger than the central angle β of the limiting ring.

[0049] This invention also proposes a method for adjusting the blade tip clearance using an adjustment structure, comprising the following steps: measuring the first blade tip clearance (δ1) on the impeller inlet side and the second blade tip clearance (δ0) on the outlet side; determining the required axial displacement adjustment amount (Δδ) of the insert ring based on the deviations of δ1 and δ0 from the design target values; operating the axial adjustment device under the real-time signal guidance of the displacement monitoring device to move the insert ring by the axial displacement adjustment amount Δδ; re-measuring δ1 and δ0 to verify the adjustment result.

[0050] The present invention also proposes a predictive maintenance method based on an adjustment system, specifically: continuously recording the displacement data output by the displacement monitoring device; when the displacement data indicates that the insert ring has moved close to the maximum stroke limited by the limit ring, generating an early warning for insert ring wear and replacement.

[0051] Below is a specific example: To address the blind zone problem in measuring the impeller outlet side blade tip clearance, this invention proposes a unique dual-observation-hole spatial intersection measurement method, such as... Figure 2 , Figure 3 and Figure 5 As shown, two bosses 23 are provided on the pump body, and observation holes are machined on the bosses 23. The center lines of the two observation holes intersect at point H at the blade tip clearance on the impeller outlet side. Figure 5 During measurement, the flexible gap gauge is inserted through one observation hole to measure the blade tip clearance δ0 on the outlet side, and the measurement status of the gap gauge is observed through another hole.

[0052] The observation hole is designed as a threaded hole with upper and lower countersunk holes. During pump operation, the observation hole is sealed with a plug, the nut of which is submerged in the upper countersunk hole. The diameter D0 of the threaded hole is designed to be at least 30mm, and the diameter D1 of the lower countersunk hole is 10mm to 20mm larger than the threaded diameter D0. The angle θ between the centerline of the observation hole and the centerline of the pump shaft is designed to be 55° to 90°. The two observation holes are symmetrical about the centerline OH, the angle ε between the centerline OH and the vertical axis is designed to be 30° to 60°, and the angle γ between the centerlines of the two holes is designed to be 60° to 90°.

[0053] The design ranges of included angles θ, ε, γ and diameters D0, D1 have been analyzed and verified to ensure that the flexible gap gauge can be accurately guided to the gap to be measured. While minimizing disturbance to the medium in the pump body and ensuring the strength of the pump body, it provides sufficient adjustment space and a good observation field, which makes the measurement of δ0 intuitive and feasible, and solves the problem of the impeller outlet side blade tip gap being unmeasurable.

[0054] After measuring the clearance δ0, the first blade tip clearance δ1 on the impeller inlet side is measured using a feeler gauge. The clearances δ0 and δ1 are compared with the design target value δ. Based on the geometric relationship between the impeller and the insert ring, the theoretical axial displacement of the insert ring required to adjust the inlet and outlet clearances to the target values ​​is calculated respectively. The required displacement on the outlet side is: Δδ0 = (δ0 - δ) / sinψ0; The required displacement on the inlet side is: Δδ1 = (δ1 - δ) / sinψ1.

[0055] Wherein, ψ0 is the angle between the blade outlet edge of the impeller near the end face of the insertion ring and the pump shaft centerline; ψ1 is the angle between the blade inlet edge of the impeller near the end face of the insertion ring and the pump shaft centerline; both are determined by the inherent structural parameters of the impeller.

[0056] Then, a comprehensive analysis of the calculated Δδ0 and Δδ1 is performed to determine an optimal axial displacement Δδ of the insert ring. This Δδ ensures that the adjusted clearances δ0 and δ1 simultaneously approach or meet their design tolerance requirements, thereby accurately achieving coordinated optimization adjustment of the tip clearances on the inlet and outlet sides.

[0057] To address the issue of repeated disassembly and reassembly, this invention designs a through-type axial displacement adjustment mechanism.

[0058] like Figure 2 and Figure 3 As shown, without changing the external dimensions of the sewage pump, a through-type adjusting screw and a guide section are provided on the suction cover 3 and the insertion ring 4. The adjusting screw 16 includes a threaded portion 1601 and a smooth rod portion 1602 at the end, and the smooth rod portion 1602 is provided with a milled flattened part 1603 for clamping.

[0059] A threaded hole for installing an adjusting screw is provided on the insertion ring 4, and a smooth hole for mates with the adjusting screw is provided on the suction cover. Countersunk holes are provided at both the front and rear ends of both the threaded hole and the smooth hole. The adjusting screw is screwed into the threaded hole at the front end of the insertion ring, and then locked at the rear end of the insertion ring with a nut 20. The insertion ring 4 is then slid along the guide section 301 provided on the suction cover 3, and the adjusting screw extends through the smooth hole on the suction cover to the outside of the pump, where it is locked to the outside of the suction cover by the nut. A combination of spring washers 22 and hard washers is used at all threaded locking points to ensure the reliability of the threaded connection and the uniformity of force distribution.

[0060] Adjust the axial displacement of the insert ring according to Δδ. First, loosen the nut and washer on the outside of the suction cover. Use a tool to clamp the milled flattened part on the adjusting screw and push the adjusting screw to make it slide the insert ring along the guide section. The dimensional fit tolerance between the insert ring and the guide section of the suction cover is H7 / h6. The number of adjusting screws can be 3 to 6, evenly distributed along the circumference. The pitch circle size and screw size can be adjusted according to actual needs.

[0061] To prevent corrosion of the threads of the adjusting screw 16, stainless steel is selected and its surface is sprayed. First sealing rings 19 are also provided inside the hard washers 18 on both the adjusting screw nut and the end nut. A detachable nut protective sleeve 17 is provided on the nut 20 at the end of the adjusting screw 16 to protect the nut and the threaded portion on its outer side.

[0062] The design of the through-type adjusting screw and guide section transforms the insert ring into a component that can be driven outside the pump and slide precisely along the guide section. This enables the axial movement of the insert ring to be directly driven outside the pump and the impeller tip clearance to be adjusted, eliminating the tedious steps of frequent disassembly and assembly and making the adjustment operation continuous and controllable.

[0063] To accurately control the adjustment results, this invention integrates a magnetostrictive displacement sensor real-time monitoring unit on the insertion ring and the suction cap.

[0064] like Figure 2 and Figure 4 As shown, a waterproof magnetostrictive displacement sensor 8 is installed on the suction cover 3, and a magnetic ring 10 is installed at a corresponding position at the rear end of the insertion ring 4. The magnetic ring 10 is fixed to the insertion ring 4 with a demagnetizing screw. When the insertion ring 4 moves axially, the magnetic ring moves accordingly. The sensor waveguide is built-in, and a waveguide mounting hole is provided at the rear end of the insertion ring. The size of the sensor can be selected according to structural requirements.

[0065] This unit converts the axial displacement of the insertion ring into a high-precision digital signal in real time, providing accurate displacement feedback for the adjustment process and enabling precise quantitative adjustment of the impeller tip clearance. The magnetostrictive displacement sensor's non-contact measurement principle avoids component wear, ensuring the long-term accuracy and reliability of the displacement feedback signal.

[0066] When the axial displacement of the insertion ring reaches Δδ, install the nut and washer on the outside of the suction cover, and then verify the gap on both sides respectively.

[0067] To ensure the safe and effective operation of the sensor, a second sealing ring 21 is provided on the guide section of the insertion ring to isolate the medium outside the sensor cavity. When the axial movement of the insertion ring is too large, the second sealing ring may lose its mating surface, thus causing sealing failure. Therefore, to ensure the sealing effect, a limiting ring 12 is provided between the suction cover and the insertion ring to limit the axial movement distance of the insertion ring.

[0068] like Figure 2 , Figure 3 , Figure 6-2 , Figure 6-2 , Figure 7 and Figure 8As shown, the limiting ring 12 is designed as a fan-shaped annular structure, with fan-shaped annular grooves E and F machined on the insertion ring and suction cover. After the suction cover and insertion ring are assembled, the limiting ring is placed into the groove. An annular groove D is provided on the limiting ring, and screws are installed through the annular groove D to fix the limiting ring to the suction cover. The central angle β of the limiting ring is designed to be 60°–90°, and the size of the screw holes on the limiting ring is selected according to the actual structure, with a quantity of 3–5. To facilitate the installation of the limiting ring, the central angle α of the fan-shaped annular grooves on the suction cover and insertion ring is 2°–3° larger than the central angle β of the limiting ring.

[0069] The distance S0 between the limiting ring (surface B) and the insert ring (surface C) is the maximum allowable axial movement of the insert ring. Considering the guide length required for seal installation, the distance S1 between the left end face of the suction cap and the upper sealing groove of the guide section needs to be at least 5mm larger than S0. When the axial movement of the insert ring reaches S0, the limiting ring (surface B) and the insert ring (surface C) contact, and the axial movement of the insert ring is restricted. The distance S0 can be designed according to actual needs.

[0070] In this embodiment, a limit ring is installed, which not only provides mechanical limitation but also locks the effective measurement range of the sensor with the safe operating range of the adjustment system. This prevents measurement and sealing failures caused by over-adjustment, thus improving the inherent safety and reliability of the adjustment system. Simultaneously, when the sensor detects that the axial displacement of the insertion ring approaches S0, it not only means that the adjustment margin is almost exhausted but also indicates that the wear on the insertion ring end face has reached the replacement threshold, thereby achieving a digital early warning of mechanical wear life.

[0071] like Figure 3 and Figure 6-1 and 6-2 As shown, a labyrinth seal 1201 is provided on the inner diameter of the limiting ring 12 to prevent dirt from accumulating in the G cavity between the limiting ring and the insertion ring and affecting the adjustment effect.

[0072] like Figure 8 As shown, scraping grooves 14 are provided on the end face of the insertion ring. The number of scraping grooves 14 is designed to be 1 to 2, and the specific size can be adjusted according to actual needs. This design ensures that the impeller and the end face of the insertion ring are not easily jammed in media containing long fibers or flexible impurities, thereby ensuring the effectiveness of the blade tip clearance as an adjustable parameter and maintaining the core function of the entire adjustment system.

[0073] This invention constructs a collaborative adjustment system that integrates "precise measurement, external adjustment, and displacement feedback".

[0074] First, to address the problem of blind spots in the measurement of impeller outlet side blade tip clearance, this invention proposes a unique dual-observation-hole spatial intersection measurement method. By setting two observation holes on the pump body whose centerlines intersect at the impeller outlet side blade tip clearance, a direct and visualized measurement of the semi-open impeller outlet side blade tip clearance can be achieved without disassembling any components, thus obtaining a complete adjustment basis.

[0075] Secondly, to address the issue of repeated disassembly and assembly, this invention designs a through-type axial displacement adjustment mechanism. This mechanism, through adjusting screws and guide sections, transforms the insertion ring into a movable component that can be driven outside the pump and slide along the guide section. This enables direct axial movement of the insertion ring from outside the pump, adjusting the impeller tip clearance, thereby eliminating the tedious steps of frequent disassembly and assembly, and making the adjustment operation continuous and controllable.

[0076] Finally, to transform the adjustment process from subjective experience to precise control, this invention integrates a magnetostrictive displacement sensor real-time monitoring unit on the insertion ring and the suction cover. This unit converts the axial displacement of the insertion ring into a high-precision digital signal, providing real-time feedback on the axial displacement of the insertion ring during adjustment, thereby achieving precise quantitative adjustment of the impeller tip clearance.

[0077] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as defined by the appended claims and their equivalents.

Claims

1. A high-efficiency adjustment system for the tip clearance of a semi-open impeller of a sewage pump, characterized in that: The semi-open impeller tip clearance high-efficiency adjustment system for the sewage pump includes a pump body, impeller, suction cover, and insertion ring, and also includes: A clearance measuring device is used to directly obtain the blade tip clearance value on the outlet side of the impeller; An axial adjustment device, connecting the suction cover and the insertion ring, is used to drive the insertion ring to move axially along the suction cover from outside the pump body; A displacement monitoring device is used to monitor the axial displacement of the insertion ring in real time and output a feedback signal; The feedback signal of the displacement monitoring device is used to indicate the real-time displacement of the insert ring under the drive of the axial adjustment device, so as to compare it with the target displacement calculated based on the measurement results of the gap measuring device, thereby completing the adjustment of the blade tip clearance; The clearance measuring device includes a first observation hole and a second observation hole that are opened on the pump body and communicate with the pump cavity. The center lines of the first observation hole and the second observation hole intersect in the region where the blade tip clearance is located on the impeller outlet side. The axial adjustment device includes at least three adjusting screws, the threaded part of which is connected to the threaded part of the insertion ring, and the smooth part of which passes through the smooth hole on the suction cover and is fixed to the outside of the suction cover by a locking component; The displacement monitoring device is a magnetostrictive displacement sensor. The waveguide of the magnetostrictive displacement sensor is fixed inside the suction cover, and a magnetic ring corresponding to the waveguide is fixed on the insertion ring. Both the first and second observation holes are threaded holes and equipped with sealing plugs; the angle θ between the centerline of the first and second observation holes and the centerline of the pump shaft is 55° to 90°, the angle γ between the centerlines of the first and second observation holes is 60° to 90°, and the angle ε between the symmetrical centerline of the first and second observation holes and the vertical axis is 30° to 60°. It also includes a limiting ring located between the suction cover and the insertion ring to limit the maximum axial movement of the insertion ring. At least one scraping groove is provided on the end face of the insertion ring opposite to the impeller. The limiting ring is designed as a fan-shaped ring structure, with fan-shaped annular grooves E and F machined on the insertion ring and suction cover. After the suction cover and insertion ring are assembled, the limiting ring is placed into the groove. An annular groove D is provided on the limiting ring, and screws are installed through the annular groove D to fix the limiting ring to the suction cover. The central angle β of the limiting ring is designed to be 60° to 90°. To facilitate the installation of the limiting ring, the central angle α of the fan-shaped annular grooves on the suction cover and insertion ring is 2° to 3° larger than the central angle β of the limiting ring.

2. The high-efficiency adjustment system for the semi-open impeller tip clearance of the sewage pump according to claim 1, characterized in that: A waterproof magnetostrictive displacement sensor is installed on the suction cap, and a magnetic ring is installed at the corresponding position at the rear end of the insertion ring. The magnetic ring is fixed to the insertion ring with a demagnetizing screw. When the insertion ring moves axially, the magnetic ring moves accordingly. The waveguide of the magnetostrictive displacement sensor is built-in, and a waveguide mounting hole is provided at the rear end of the insertion ring.

3. A method for adjusting blade tip clearance using the adjustment system as described in claims 1-2, comprising the following steps: Measure the first blade tip clearance δ1 on the impeller inlet side and the second blade tip clearance δ0 on the outlet side; determine the required axial displacement adjustment Δδ of the insert ring based on the deviations of δ1 and δ0 from the design target values; operate the axial adjustment device under the real-time signal guidance of the displacement monitoring device to move the insert ring by the axial displacement adjustment Δδ; remeasure δ1 and δ0 to verify the adjustment results; The displacement data output by the displacement monitoring device is continuously recorded; when the displacement data indicates that the insertion ring has moved close to the maximum stroke limited by the limiting ring, an insertion ring wear and replacement warning is generated.

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