Method for adjusting axis of mixed flow pump set

Abstract

The application discloses a mixed-flow pump set axis adjusting method and relates to the technical field of water conservancy and hydropower, which comprises the following steps: S1: overall debugging the mixed-flow pump set, installing the anti-weight plate of the thrust bearing after completing pre-installation of the upper rack; S2: taking the anti-weight plate as a reference surface, sequentially installing an insulating pad, an insulating sleeve, a thrust pad and a thrust head, and completing installation of the thrust head; S3: utilizing disc wheel adjustment to adjust the clearance of the thrust bearing, and obtaining corresponding full swing and net swing; and S4: calculating the pad holding clearance of each part according to the full swing and net swing of each part of the shafting after adjustment, and adjusting the axis according to the pad holding clearance. The application can improve the service life of the bearing, reduce the vibration swing of the unit, effectively control the oil temperature rise of the bearing and the like, and improve the operation condition of the unit.

Description

Technical Field

[0001] This invention relates to the field of water conservancy and hydropower technology, and more specifically to a method for adjusting the axis of a mixed-flow pump set. Background Technology

[0002] Currently, in the entire construction process of pump station pump unit installation, the shaft adjustment of the motor and water pump is the most crucial construction procedure. Its quality directly affects the stable and long-term operation of the pump unit under complex working conditions. With the continuous improvement of equipment manufacturing and application technologies, higher demands are being placed on our on-site installation techniques. Shaft adjustment is the core procedure of the entire unit installation, and its quality directly affects the safe operation of the water pump. Proper shaft adjustment can improve bearing life, reduce unit vibration and runout, and effectively control bearing oil temperature rise, thus improving the unit's operating conditions.

[0003] However, due to manufacturing tolerances, installation errors, and cumulative errors after installation, the shaft's centerline during operation revolves around a trajectory that deviates from the theoretical centerline by a certain angle and radius. If the shaft is not adjusted in time, it can easily reduce the overall lifespan of the unit. Existing technology lacks a relevant adjustment process.

[0004] Therefore, how to provide a method for adjusting the axis of a mixed-flow pump group that can solve the above problems is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a method for adjusting the axis of a mixed-flow pump set, which can improve the service life of bearings, reduce the vibration and runout of the unit, and effectively control the temperature rise of bearing oil, thereby improving the operating conditions of the unit.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for adjusting the axis of a mixed-flow pump unit, applied to a mixed-flow pump unit, including an upper frame, stator, thrust bearing, motor turning gear, and pump unit guide bearing, includes the following steps:

[0008] S1: Perform overall debugging of the mixed flow pump group, and after completing the pre-installation on the frame, install the anti-weight plate of the thrust bearing;

[0009] S2: Using the anti-weight plate as the reference surface, install the insulating pad, insulating sleeve, thrust plate and thrust head in sequence to complete the installation of the thrust head;

[0010] S3: Adjust the clearance of the thrust bearing by turning the rotary lobe to obtain the corresponding full runout and net runout;

[0011] S4: Calculate the bearing clearance at each part based on the full runout and net runout at each part of the adjusted shaft system, and adjust the shaft according to the bearing clearance.

[0012] Preferably, S1 specifically includes:

[0013] S11: Measure the levelness value of the anti-weight plate using a level and compare the levelness value with a preset threshold;

[0014] S12: No adjustment is made when the levelness value is less than or equal to the preset threshold.

[0015] S13: When the levelness value is greater than the preset threshold, the adjustment is made by adding or removing metal shims on the contact surface between the upper frame and the stator.

[0016] Preferably, S2 specifically includes:

[0017] S21: Heat the thrust head until the mating dimensions reach a preset range value before installation;

[0018] S22: During installation, the insulating pad, the insulating sleeve, the thrust bearing and the thrust head are installed in sequence.

[0019] Preferably, S3 specifically includes:

[0020] S31: The thrust head is divided into 8 equal divisions and the marked points are numbered. A dial indicator is placed at each marked point.

[0021] S32: Push the rotary table and record the data of the dial gauge each time it rotates 45°;

[0022] S33: Obtain the corresponding full swing and net swing based on the data from the dial gauge.

[0023] Preferably, S4 specifically includes: adjusting the axis by adding a shim or scraping a flange at the thrust shaft.

[0024] As can be seen from the above technical solution, compared with the prior art, this invention discloses a method for adjusting the axis of a mixed-flow pump set, employing static quality control and dynamic axis detection methods for adjusting the unit's axis. Through dynamic turning data analysis and calculation, it solves the problems of potential axis non-perpendicularity and axis bending, meeting the stable operation requirements of the pump set under various working conditions. This technology shortens the construction period, reduces labor intensity, and improves the quality and construction efficiency during the pump set installation and axis adjustment process. The various technical indicators of the pump set's axis are strictly controlled through the turning adjustment method, reducing the unbalanced forces on rotating parts during unit operation. It minimizes the impact of magnetic and hydraulic imbalances on unit operation, ensuring the unit maintains a stable operating state. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0026] Figure 1 A flowchart of an overall method for adjusting the axis of a mixed-flow pump set provided by the present invention;

[0027] Figure 2 This is a schematic diagram of the anti-weight plate adjustment provided in an embodiment of the present invention. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] See appendix Figure 1 As shown, this invention discloses a method for adjusting the axis of a mixed-flow pump set, applied to a mixed-flow pump set, including an upper frame, stator, thrust bearing, motor turning gear, and pump set guide bearing, comprising the following steps:

[0030] S1: Perform overall debugging of the mixed flow pump unit, and after completing the pre-installation on the frame, install the anti-weight plate of the thrust bearing;

[0031] S2: Using the anti-weight plate as the reference surface, install the insulating pad, insulating sleeve, thrust plate and thrust head in sequence to complete the installation of the thrust head;

[0032] S3: Adjust the clearance of the thrust bearing by turning the gearbox to obtain the corresponding total runout and net runout;

[0033] S4: Calculate the bearing clearance of each part based on the total runout and net runout of each part of the shaft system after adjustment, and adjust the shaft according to the bearing clearance.

[0034] Specifically, the installation work before axis adjustment includes:

[0035] (1) Pump base installation completed: The deviations of the pump base foundation, pump base center, elevation, level and other technical indicators from the construction survey network benchmark points meet the requirements. After acceptance, the second phase of concrete pouring is completed, and the concrete strength and other indicators meet the requirements after curing.

[0036] (2) The impeller chamber, suction horn pipe section, and guide cone are hoisted into the pit and constructed according to the drawings. Check that the installation of each component and its external dimensions meet the design requirements. After meeting the requirements, the suction horn pipe and impeller chamber (segmented) are disassembled and placed at the bottom of the pit; the guide cone is placed at the approximate position of the unit center, and then adjusted and installed after the unit center is adjusted.

[0037] (3) Impeller installation. Before installation, a leakage test is conducted. After all tests are passed, the impeller is hoisted to a near elevation using a bridge crane. Then, a winch and rollers are used to position the impeller on the installation platform, directly opposite the center of the pump shaft. The pump shaft is then hoisted to the impeller chamber and connected to the impeller. The impeller is then lowered into the machine pit and placed on the corresponding elevation, center platform.

[0038] (4) Clean the guide vane body and intermediate connecting pipe at the installation site, and assemble them. The gap between the assembled parts should not be able to be filled with a 0.05mm feeler gauge. Hoist the entire assembly into the machine pit for installation. Recheck the center, elevation, and level. After confirming that the design requirements are met, tighten the bolts and drill pin holes to align with the pump base. After the guide vane body is installed correctly, use the lower guide bearing hole as the reference for measuring the vertical coaxiality of the pump unit. Suspend a piano line; the center reference line error should not exceed 0.05mm. Use this piano line as the center reference for the bends, the upper and lower frames of the motor, and the stator.

[0039] (5) Clean and grind the flange face of the intermediate pipe and the 60° bend pipe section, and re-measure its center, level and elevation. After meeting the requirements, install the 60° bend pipe section. The flange face is considered qualified if it cannot pass through the gauge measured with a 0.05mm feeler gauge. Install the 30° bend pipe section, expansion joint and outlet pipe section in the same way.

[0040] (6) The lower frame and stator of the motor are installed on the same foundation. First, when pouring the concrete for the motor layer, four foundation plates with a diameter of 12mm are embedded. Before hoisting, four pairs of wedge plates are placed, and then the lower frame and stator are hoisted separately, while the upper frame is hoisted in for pre-installation. After the lower frame, stator, and upper frame are in place, their center, elevation, and level are adjusted, and the following requirements should be met, with the stator as the main component: 1) The center deviation between the upper and lower frames does not exceed 1mm; 2) The horizontal deviation does not exceed 0.10mm / m; 3) The elevation deviation does not exceed ±1.5mm; 4) The difference between each radius of the center and the average radius should be <±4% of the design air gap; 5) The stator installation elevation is checked according to the magnetic field centerline, and the average centerline of the stator core should be equal to or higher than the average centerline of the rotor magnetic poles, and the excess value should not exceed 0.5% of the effective length of the stator core. After passing the inspection, reinforcement is carried out. The positioning pins of the upper frame are drilled and removed, and the lower frame and stator foundation are handed over for the second-stage concrete pouring.

[0041] (7) Hoist the pump shaft to the impeller chamber and connect it to the impeller. After the pump shaft and impeller are connected, hoist the impeller chamber and the suction bell pipe section.

[0042] (8) Rotor hoisting. The rotor is hoisted and slowly lowered onto the brake, taking special care to prevent the rotor from rubbing against the stator and to prevent the generator shaft from colliding with the water pump shaft. After the rotor is hoisted into place, the pump set installation work enters a series of key processes such as upper frame installation, bearing installation, and shaft adjustment.

[0043] In one specific embodiment, S1 specifically includes:

[0044] S11: Measure the levelness value of the anti-weight plate using a level and compare the levelness value with a preset threshold;

[0045] S12: No adjustment will be made when the levelness value is less than or equal to the preset threshold;

[0046] S13: When the levelness value is greater than the preset threshold, it can be adjusted by adding or removing metal shims at the contact surface between the upper frame and the stator.

[0047] Specifically, the suspended upper frame is mounted on the top surface of the stator. The upper frame is pre-assembled during stator installation, and its center, elevation, levelness, and other parameters have been preliminarily adjusted and positioned using locating pins in the previous step. The thrust bearing anti-weight plate is generally mounted on the upper frame. In thrust bearing units with a self-adjusting elastic washer structure, the levelness requirements for the thrust bearing anti-weight plate are high. The levelness error adjustment of the upper frame is mainly based on quality control using the top surface of the anti-weight plate as a reference.

[0048] During the pre-installation and adjustment of the upper frame, attention should be paid to controlling its installation elevation in advance. Since the elevation of the thrust bearing with elastic washer structure cannot be compensated and adjusted when the upper frame is positioned, the installation elevation of the top surface of the anti-weight plate should be calculated in advance based on the combined height of the elastic washer, thrust bearing and mirror plate, and then adjusted accordingly.

[0049] See appendix Figure 2 As shown, the upper frame anti-weight plate has a ring structure. During the installation of the thrust bearing housing, it is confirmed by placing it along the tangential direction in different orientations using instruments such as a frame level or a phase level, and then turning it around and measuring repeatedly on the spot. Eight measuring points are measured in the circumferential direction from +X to -Y to -X to +Y. The actual horizontal error is taken as the average of the two sides. The horizontal error of the anti-weight plate position is generally controlled within the range of 0.02mm / m. If the error exceeds the allowable range, it can be adjusted by adding or removing metal shims at the mating surface between the upper frame and the stator. The metal shims should ensure that the contact surface shape and size with the mating surface are basically the same to prevent loosening during operation.

[0050] After the elevation and levelness of the top surface of the anti-weight plate meet the requirements, tighten the assembly bolts and install the positioning pins, and then conduct a re-measurement and inspection.

[0051] In one specific embodiment, S2 specifically includes:

[0052] S21: Heat the thrust head until the mating dimensions reach the preset range value before installation;

[0053] S22: During installation, install the insulating pad, insulating sleeve, thrust pad, and thrust head in sequence.

[0054] Specifically, before installing the thrust bearing, the combined height of the elastic washer and the thrust bearing should be measured with a depth gauge. Since the processing dimensions of the elastic washer and the thrust bearing will vary, the position of each component should be adjusted according to the combined height to ensure that the combined height is basically consistent in the circumferential and symmetrical positions based on the anti-weight plate as the reference surface, and the combined height error should be controlled within 0.04mm.

[0055] Since the spindle and thrust head have an interference fit, a heat-shrink method is generally used to install the thrust head onto the spindle. Before installation, the spindle and thrust head are cleaned. The thrust head is heated using an eddy current heating method. During heating, the inner diameter of the thrust head and the outer diameter of the shaft are measured. The thrust head is then assembled when the fit reaches a single-sided clearance of approximately 0.1–0.2 mm. After assembly, a retaining ring is installed to secure the thrust head.

[0056] When connecting the mirror plate to the thrust head, ensure the insulation pad and insulation sleeve are clean, and measure the insulation resistance to ensure it meets the insulation requirements.

[0057] In a specific embodiment, S3 specifically includes:

[0058] S31: Mark the thrust head with 8 equal divisions and number the marked points, and place a dial indicator at each marked point;

[0059] S32: Push the rotary carriage and record the dial gauge data each time it rotates 45°;

[0060] S33: Obtain the corresponding full swing and net swing based on the data from the dial gauge.

[0061] Specifically, a dynamic monitoring method is used to adjust the motor shaft axis by rotating it individually. Based on the rotation data of the lower guide shaft, the correction value of the part with excessive runout is calculated, and the amount of insulation pad scraping correction at the thrust head is determined. The runout value of each part of the motor shaft and the levelness of the thrust head and other technical indicators are adjusted to the required range.

[0062] The manual rotation of the water pump plays a crucial role in pump installation. Adjusting the pump shaft through rotation can eliminate tilting and kinks in the pump unit's axis, significantly improving the performance of components such as bearings and reducing swaying and vibration during operation. The data from the manual rotation adjustment guides the adjustment of clearances in various guide bearings.

[0063] 1. After the thrust bearing is installed and adjusted before turning the gear, the thrust bearing is evenly stressed and the levelness error is ≤0.02mm / m. Make 8 equal division marks on the thrust head, upper guide shaft, lower guide shaft and water guide shaft and number the measuring points.

[0064] 2. Install four guide bearings symmetrically or three guide bearings in equal divisions on the upper guide bearing, and adjust the main shaft to be in the center position. The bearings and thrust bearings generally use lard with a low coefficient of friction as a lubricant.

[0065] 3. Dial indicators are installed in the X and Y directions of the upper guide shaft collar, lower guide shaft collar, motor flange, and water guide shaft collar. The dial indicators at different levels are aligned according to the vertical line position.

[0066] 4. Pump unit rotation is usually achieved manually, with a rotating device installed at the end of the shaft. Dial gauges on each level are monitored and recorded by designated personnel, with unified command during rotation. The corresponding value is recorded each time the pump unit rotates 450 degrees or at each measuring point.

[0067] 5. Calculate the total runout and net runout based on the relative points corresponding to the readings at each measuring point to determine the inclination of the shaft. Adjust the runout values ​​at various points on the shaft to within the acceptable range by scraping the insulating shims at the thrust head.

[0068] In one specific embodiment, S4 specifically includes:

[0069] Axis adjustment is achieved by adding shims or scraping flanges at the thrust shaft.

[0070] Based on the actual runout values ​​at various points in the adjusted shaft system, the bearing clearance at each location is calculated to ensure that all bearings remain within the actual center of motion of the shaft system. This ensures that all bearings within the shaft system are synchronized with the center of motion, preventing uneven wear, stiffness, and other issues that could damage the bearings. Since errors exist in the actual shaft axis, the clearance adjustment of each guide bearing is guided by the actual runout of the shaft at each location, ensuring that the guide bearing at each location is concentric with the shaft's trajectory. This adjustment method ensures even stress distribution on all bearings, reducing pump unit vibration.

[0071] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0072] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for adjusting the axis of a mixed-flow pump set, applied to a mixed-flow pump set, comprising an upper frame, a stator, a thrust bearing, a motor turning gear, and a pump set guide bearing, characterized in that, Includes the following steps: S1: Perform overall debugging of the mixed flow pump group, and after completing the pre-installation on the frame, install the anti-weight plate of the thrust bearing; S2: Using the anti-weight plate as the reference surface, install the insulating pad, insulating sleeve, thrust plate and thrust head in sequence to complete the installation of the thrust head; S3: Adjust the clearance of the thrust bearing by rotating the motor to obtain the corresponding full runout and net runout; S4: Calculate the bearing clearance at each part based on the full runout and net runout at each part of the adjusted shaft system, and adjust the shaft according to the bearing clearance.

2. The method for adjusting the axis of a mixed-flow pump set according to claim 1, characterized in that, S1 specifically includes: S11: Measure the levelness value of the anti-weight plate using a level and compare the levelness value with a preset threshold; S12: No adjustment is made when the levelness value is less than or equal to the preset threshold. S13: When the levelness value is greater than the preset threshold, the adjustment is made by adding or removing metal shims on the contact surface between the upper frame and the stator.

3. The method for adjusting the axis of a mixed-flow pump set according to claim 1, characterized in that, S2 specifically includes: S21: Heat the thrust head until the mating dimensions reach a preset range value before installation; S22: During installation, the insulating pad, the insulating sleeve, the thrust bearing and the thrust head are installed in sequence.

4. The method for adjusting the axis of a mixed-flow pump set according to claim 3, characterized in that, S3 specifically includes: S31: The thrust head is divided into 8 equal divisions and the marked points are numbered. A dial indicator is placed at each marked point. S32: Push the motor to rotate the wheel, and record the data of the dial gauge each time it rotates 45°; S33: Obtain the corresponding full swing and net swing based on the data from the dial gauge.

5. The method for adjusting the axis of a mixed-flow pump set according to claim 1, characterized in that, S4 specifically includes: Axis adjustment is performed by adding shims or scraping flanges at the thrust bearing.

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