A special tool for measuring the vertical shaft flow pump stator and rotor center height difference

Abstract

The utility model relates to vertical axial flow pump technical field, concretely relates to a special tool for measuring vertical axial flow pump stator and rotor center height difference, including water inlet horn and casing, and the casing includes guide vane body and elbow pipe, the upper surface of water inlet horn sets up guide vane body, and impeller assembly is set up below in guide vane body. The utility model can be detachably arranged in the inside of casing through chuck, because the chuck claw of chuck is movable setting, chuck can be supported in the inside of casing through chuck claw, and chuck can adapt to the casing of different inner diameters after the movement of chuck claw, because it can solve the poor adaptability problem of different models vertical axial flow pump, adopts the grating micrometric sensor of 0.001mm resolution and solves the problem of insufficient measurement accuracy, and the chuck is arranged in the inside of casing, realizes the measurement process in the casing, and reduces the preparation work before testing.

Description

Technical Field

[0001] This utility model relates to the field of vertical axial flow pump technology, specifically to a special tool for measuring the height difference between the stator and rotor centers of a vertical axial flow pump. Background Technology

[0002] During the installation and maintenance of large vertical axial flow pumps, the center height difference between the stator and rotor is a core parameter directly affecting the pump's operating efficiency and service life. If this height difference exceeds the allowable range, the rotor will rub against the stator or experience abnormal vibration during operation, leading to a chain of failures such as bearing overheating and seal failure, and in severe cases, even causing the entire pump to be scrapped. However, current methods for measuring this critical parameter have significant drawbacks: First, the measurement accuracy is insufficient. Traditional methods often rely on a combination of a level and a steel ruler, requiring multiple manual readings and numerical conversions. This is not only cumbersome but also easily affected by factors such as the operator's experience level and visual observation errors. The actual measurement error often exceeds 0.1 mm, far from meeting the stringent accuracy requirement of "allowable height difference deviation ≤ 0.05 mm" for large axial flow pumps. Second, the operation process is complex. Before measurement, a temporary platform must be set up and the tool position repeatedly adjusted. The entire process requires at least 2-3 people to work together, and during measurement... Multiple calibrations to ensure accuracy result in measurement times for a single pump typically exceeding two hours, leading to extremely low operational efficiency. Thirdly, there is poor adaptability. Due to significant differences in stator inner diameter and rotor shaft diameter among different models of vertical axial flow pumps, traditional tools require frequent replacement of multiple parts to match specific models. Furthermore, they have high requirements for measurement space, often making effective operation difficult in narrow areas within the pump body (such as the gap between the guide vane and impeller). Based on these issues, there is an urgent need to develop a dedicated measuring tool with high precision, ease of operation, and strong adaptability to effectively solve the challenge of accurately measuring the height difference between the stator and rotor centers of large vertical axial flow pumps.

[0003] Therefore, it is necessary to invent a special tool for measuring the height difference between the stator and rotor centers of a vertical axial flow pump to solve the above problems. Utility Model Content

[0004] The purpose of this invention is to provide a special tool for measuring the height difference between the stator and rotor centers of a vertical axial flow pump. The tool is detachably mounted inside the housing via a chuck. Because the chuck's jaws are movable, the chuck can be supported inside the housing by the jaws. The jaws can be moved to adapt to housings with different inner diameters, thus solving the problem of poor compatibility with different models of vertical axial flow pumps. The use of a 0.001mm resolution grating micrometer sensor solves the problem of insufficient measurement accuracy. Since the chuck is located inside the housing, the measurement process is carried out within the housing, reducing pre-test preparation work.

[0005] To achieve the above objectives, this utility model provides the following technical solution: it includes an inlet horn and a housing. The housing includes a guide vane and a bend. The guide vane is disposed on the upper surface of the inlet horn. An impeller assembly is disposed in the lower part of the guide vane. The impeller assembly is passed through the lower end of the pump shaft. The upper end of the pump shaft passes through the packing seat above the bend. A chuck is disposed at the bottom of the packing seat. A grating measuring device is disposed inside the housing. The chuck can be supported inside the housing by the jaws. After the jaws move, they can adapt to housings with different inner diameters.

[0006] Preferably, the grating measuring device includes a grating reading head and a grating target, with the grating reading head disposed on the lower surface of the chuck and the grating target disposed on the top of the impeller assembly.

[0007] Preferably, the data cable of the grating reading head is connected to the display screen through the housing, and the display screen is disposed outside the housing.

[0008] Preferably, the chuck is a three-jaw chuck.

[0009] Preferably, a coil sensor is disposed outside the housing in both the X and Y directions, with the coil sensor facing the pump shaft.

[0010] This utility model also provides a special tool for measuring the height difference between the stator and rotor centers of a vertical axial flow pump, including an inlet horn and a housing. The housing includes a guide vane and a bend. The guide vane is provided on the upper surface of the inlet horn. An impeller assembly is provided in the lower part of the guide vane. The impeller assembly is passed through the lower end of the pump shaft. The upper end of the pump shaft passes through the packing seat above the bend. A horizontal track is provided inside the bend. A grating reading head is provided on the track. A grating target is provided on the upper surface of the impeller assembly.

[0011] Preferably, the grating reading heads are arranged in an equally spaced array of 3 to 6, and the grating targets are arranged in a vertical direction of 3 to 6.

[0012] Preferably, the grating target and the impeller assembly are connected by a damping ring.

[0013] The technical effects and advantages provided by this utility model in the above technical solution are as follows: The jaws abut against the inner surface of the housing, meaning the chuck can be supported inside the housing by the jaws. The jaws can adapt to housings with different inner diameters after they move. The grating reading head is fixed on the non-rotating part, i.e., the chuck, and the grating target is fixed on the rotating part, i.e., the top of the impeller assembly, forming a high-precision measurement link for "fixed-rotation" relative displacement. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0015] Figure 1 This is a perspective view of Embodiment 1 of the present invention without the guide vane and the chuck; Figure 2 This is a side view of Embodiment 1 of the present invention without the guide vane and the chuck; Figure 3 This is a perspective view of Embodiment 2 of the present invention; Figure 4 This is a side sectional view of Embodiment 3 of the present invention; Explanation of reference numerals in the attached figures: 100. Inlet horn; 200. Casing; 201. Guide vane; 202. Bend; 300. Impeller assembly; 400. Pump shaft; 500. Packing seat; 600. Chuck; 700. Grating readout head; 701. Grating target; 800. Display screen; 900. Coil sensor; 901. Track. Detailed Implementation

[0016] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0017] Example 1: This utility model provides the following... Figure 1-2 The tool shown is a special tool for measuring the height difference between the stator and rotor centers of a vertical axial flow pump. It includes an inlet horn 100 and a housing 200. The inlet horn 100 is located at the bottom of the device and serves as an inlet guide component for the incoming flow, so that the water flow enters smoothly and reduces the impact of inflow disturbance on the measurement. Its upper surface is rigidly connected to the guide vane body 201 to form the lower reference surface of the measuring point and the fluid channel inlet.

[0018] The housing 200 includes a guide vane 201 and a bend 202. The housing 200 is an outer housing 200 formed by the guide vane 201 and the bend 202, which provides structural support and flow channel shaping. It is fixed to the upper surface of the water inlet horn 100 to form a closed measurement cavity that is isolated from the external environment, while providing installation and protection space for internal sensors and wiring.

[0019] A guide vane 201 is provided on the upper surface of the inlet horn 100. The guide vane 201 is located above the inlet horn 100 and provides an installation cavity for the impeller assembly 300 inside. Its flow channel function is to rectify the rotational component of the water flow out of the impeller into axial flow, reduce turbulence and eddies, improve the stability of the flow field at the measuring point, and indirectly improve the repeatability of displacement / gap measurement.

[0020] An impeller assembly 300 is installed inside the lower part of the guide vane body 201. The impeller assembly 300 is arranged inside the lower part of the guide vane body 201, and is passed through by the lower end of the pump shaft 400 and cooperates with it to transmit torque. Its top serves as a mechanical reference surface on the rotor side, which is used to define the spatial position of the rotor in the measurement section.

[0021] The impeller assembly 300 is passed through the lower end of the pump shaft 400, which is connected to the impeller. The upper end of the pump shaft 400 passes through the impeller assembly 300 and is connected to the upper unit via the packing seat 500 above the bend 202. The bend 202 is located on the upper part of the casing 200, receiving the flow from the guide vane 201 and realizing the flow direction conversion. The packing seat 500 is installed above the bend 202 for sealing and axial positioning. A chuck 600 is installed below the bend 202 for mounting. During installation, the jaws abut against the inner surface of the housing 200, meaning that the chuck 600 can be supported inside the housing 200 by the jaws. After the jaws move, they can adapt to housings 200 with different inner diameters. The chuck 600 provides a rigid mounting surface and concentric positioning reference for the grating reading head 700, ensuring that the geometric relationship between the reading head and the pump shaft 400 and the impeller is stable and reproducible. The packing seat 500 provides a mounting base for the upper seal and sensor wiring, and forms a coaxial constraint with the pump shaft 400.

[0022] The upper end of the pump shaft 400 passes through the packing seat 500 above the bend 202. A chuck 600 is installed at the bottom of the packing seat 500, and a grating measuring device is installed inside the housing 200.

[0023] The grating measurement device includes a grating reading head 700 and a grating target 701. The grating reading head 700 is located on the lower surface of the chuck 600, and the grating target 701 is located on the top of the impeller assembly 300. The grating reading head 700 and the grating target 701 are arranged coaxially with the pump shaft 400 as the axis. The height difference and attitude change of the rotor relative to the housing 200 in the Z direction are directly obtained through non-contact displacement measurement. A cable channel is provided outside the housing 200 to send the reading head signal to an external display screen 800 for real-time display and recording. By fixing the grating reading head 700 on the non-rotating component (i.e., the chuck 600) and the grating target 701 on the rotating component (the top of the impeller assembly 300), a high-precision measurement link of "stationary-rotating" relative displacement is formed. The coaxial and equal-elevation arrangement of the reading head and the target ensures that the Z-direction displacement / height difference measurement is not affected by the impeller rotation. A non-contact displacement measurement link with the pump shaft as the sole axis is adopted: the grating reading head is fixed inside the housing 201, and the grating target 701 is fixed on the top of the impeller assembly 300 on the rotor side, realizing direct measurement of the "stationary-rotating" relative displacement. The "center height difference" is converted into the coaxial Z-axis displacement difference between the upper and lower measuring points, avoiding the multiple conversions and visual errors of the traditional "level + steel ruler". With the high-precision grating and coaxial equal elevation arrangement, the uncertainty introduced by reading and centering is significantly reduced, and the measurement uncertainty is converged to the order of ≤0.05 mm, meeting the stringent limit requirements of large axial flow pumps for height difference.

[0024] The data cable of the grating reading head 700 is electrically connected to the display screen 800 through the housing 200, and the display screen 800 is located outside the housing 200. This enables the visualization, storage, and traceability of measured values; the external unit can perform zero-point setting, unit conversion, peak / average statistics, and data export, facilitating linkage and archiving with maintenance records and axis adjustment results.

[0025] The chuck 600 is a three-jaw chuck, a three-jaw self-centering chuck, which consists of a chuck body, three jaws, a transmission gear set (1 large bevel gear + 3 small bevel gears), and a back surface thread (Archimedean spiral groove). Rotating any small bevel gear drives the large bevel gear and the back surface thread, causing the three jaws to move radially at equal intervals, achieving automatic centering and synchronous clamping / unlocking of the workpiece. This structure features rapid clamping and good repeatability.

[0026] Example 2: As Figure 3As shown, the difference between this embodiment and Embodiment 1 is as follows: In the X and Y directions, a coil sensor 900 is set outside the housing 200, with the coil sensor 900 facing the pump shaft 400. The coil sensor 900 (which can be an eddy current displacement sensor, with the coil sensor 900 attached to the housing 200) is arranged in the X and Y orthogonal directions outside the housing 200, with the probe facing the pump shaft 400, to synchronously acquire the radial offset and attitude change of the shaft in the horizontal direction; it is decoupled from the Z-direction grating measurement, and can output an integrated result of "center height difference + horizontal offset + tilt angle", which is convenient for quickly judging the fault mode (such as eccentricity, tilt or comprehensive deformation) and improving the detection of installation errors.

[0027] The other design schemes in this embodiment are the same as those in Embodiment 1.

[0028] Example 3: The difference between this example and Example 1 is that this example provides a special tool for measuring the height difference between the stator and rotor centers of a vertical axial flow pump, such as... Figure 4 As shown, it includes an inlet horn 100 and a housing 200. The housing 200 includes a guide vane 201 and a bend 202. The guide vane 201 is provided on the upper surface of the inlet horn 100. The inlet horn 100 + guide vane 201 + bend 202 (housing 200) is a combination of the two components. Functions: Forms a stable flow channel and lower reference surface, provides structural support and improves incoming flow conditions; rigidly connects with existing components of the unit (inlet horn 100, guide vane 201, bend 202), reduces additional alignment steps, and improves device positioning efficiency and measurement stability.

[0029] An impeller assembly 300 is installed inside the lower part of the guide vane body 201. The impeller assembly 300 is passed through the lower end of the pump shaft 400. The purpose of this design is that the upper surface of the impeller assembly 300 serves as the mechanical reference surface on the rotor side; the pump shaft 400 runs through the top and bottom and is the only axial carrier for the relative positional relationship between the stator and the rotor, ensuring that the measuring chain is consistent with the unit axis and reducing the impact of installation eccentricity on the height difference calculation.

[0030] The upper end of the pump shaft 400 passes through the packing seat 500 above the bend 202. A horizontal track is set inside the bend 202. The functions of the packing seat 500 and the bend 202 are to provide an installation base surface and coaxial constraint for the upper measuring component, and to work together with the bend 202 to complete the flow direction conversion and cavity sealing, so that the reading head mounting surface and the axis maintain a stable geometric relationship.

[0031] A grating reading head 700 is installed on the track and electrically connected to an external display screen 800. A grating target 701 is installed on the upper surface of the impeller assembly 300. The track provides linear guidance and precise positioning for the reading head, enabling fine-tuning and repeated positioning of the reading head in the horizontal direction. Multiple reading heads are arranged in an equidistant array, which can acquire displacement data of multiple Z-axis sections at the same time, used to evaluate center height difference, axis tilt angle and local deviation, improving the completeness and statistical reliability of the results. The grating target 701 serves as the rotor-side displacement reference, forming a one-to-one non-contact displacement measurement link with each reading head. As the rotor rotates, it can be used for multi-angle sampling and averaging, suppressing the influence of random vibration and installation unevenness.

[0032] The Z-axis height difference and attitude change of the rotor relative to the stator are measured directly in a non-contact manner; it works in conjunction with an external display / acquisition device. Three to six equidistant arrays of grating reading heads 700 are arranged, and three to six corresponding grating targets 701 are arranged in the vertical direction. In this embodiment, the chuck 600 is not included.

[0033] To address the "weak anti-interference capability" of existing technologies: non-contact grating measurement is not sensitive to dust and moisture; multiple reading head arrays and multi-angle sampling can average and identify vibrations and local disturbances, improving data reliability and consistency; high-precision gratings replace manual reading and conversion using "level + steel ruler", reducing human error; multi-point arrays and repeated sampling can bring measurement uncertainty to the required range of ≤0.05mm.

[0034] In this embodiment, the upper end face of the pump shaft 400 is used as the rotor-side reference, thereby converting the "center height difference" into a coaxial displacement difference between the upper and lower measuring points, significantly improving the measurement accuracy and efficiency at the assembly / maintenance site. The grating target 701 is connected to the impeller assembly 300 through a damping ring, which helps to reduce measurement errors caused by pump operating vibration. A horizontal track is set at the bend, allowing the grating reading heads to be arranged in an equidistant array (3-6 units), which can acquire displacement data of multiple Z-axis sections at once for evaluating center height difference, axis tilt angle, and local deviations, improving the completeness and statistical reliability of the results.

[0035] The other design schemes in this embodiment are the same as those in Embodiment 1.

[0036] The foregoing description only illustrates certain exemplary embodiments of the present invention. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A special tool for measuring the height difference between the stator and rotor centers of a vertical axial flow pump, comprising an inlet horn and a housing, the housing including guide vanes and a bend, characterized in that, The upper surface of the water inlet horn is provided with a guide vane body, and the lower part of the guide vane body is provided with an impeller assembly. The impeller assembly is passed through the lower end of the pump shaft, and the upper end of the pump shaft passes through the packing seat above the bend. A chuck is provided below the packing seat, and a grating measuring device is provided inside the housing. The chuck can be supported inside the housing by the jaws, and the jaws can adapt to housings with different inner diameters after they move.

2. The special tool for measuring the height difference between the stator and rotor centers of a vertical axial flow pump as described in claim 1, characterized in that, The grating measurement device includes a grating reading head and a grating target. The grating reading head is located on the lower surface of the chuck, and the grating target is located on the top of the impeller assembly.

3. The special tool for measuring the height difference between the stator and rotor centers of a vertical axial flow pump as described in claim 2, characterized in that, The data cable of the grating reading head is electrically connected to the display screen through the housing, and the display screen is set outside the housing.

4. The special tool for measuring the height difference between the stator and rotor centers of a vertical axial flow pump as described in claim 2, characterized in that, The chuck is a three-jaw chuck.

5. The special tool for measuring the height difference between the stator and rotor centers of a vertical axial flow pump as described in claim 1, characterized in that, In the X and Y directions, coil sensors are disposed on the outside of the housing, with the coil sensors facing the pump shaft.

6. A special tool for measuring the height difference between the stator and rotor centers of a vertical axial flow pump, characterized in that, The device includes an inlet horn and a housing. The housing includes a guide vane and a bend. The guide vane is disposed on the upper surface of the inlet horn. An impeller assembly is disposed in the lower part of the guide vane body. The impeller assembly is passed through the lower end of the pump shaft. The upper end of the pump shaft passes through the packing seat above the bend. A horizontal track is disposed inside the bend. A grating reading head is disposed on the track. A grating target is disposed on the upper surface of the impeller assembly.

7. The special tool for measuring the height difference between the stator and rotor centers of a vertical axial flow pump as described in claim 6, characterized in that, The grating reading heads are arranged in an equally spaced array of 3 to 6, and the grating targets are arranged in a vertical direction of 3 to 6.

8. The special tool for measuring the height difference between the stator and rotor centers of a vertical axial flow pump as described in claim 6, characterized in that, The grating target is connected to the impeller assembly via a damping ring.

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