A method of dynamic testing of rotor and stator clearances

Abstract

The present application belongs to the technical field of rotating structure test, and specifically discloses a dynamic test method for the gap between a rotor and a stator, comprising the following steps: in a stationary state, a wedge plug gauge is used to measure the cold-state gap between the rotor and the stator; in a rotating state, a second measuring part is used to measure the gap variation between the rotor and the stator, and a first measuring part is used to measure the radial deformation of the stator; the cold-state gap and the gap variation are added to obtain the real-time gap between the rotor and the stator in the rotating state, and the radial deformation and the gap variation are subtracted to obtain the real-time radial deformation of the rotor; the method has the following advantages: through the contact measurement of the first measuring part and the non-contact measurement of the second measuring part, the real-time measurement of the rotor-stator radial gap in the whole process can be realized during the working process of the component, the rotor-stator gap design of the rotating machine is supported, and the radial deformation of the rotor and the stator is calculated, thereby supporting the safety analysis of the rotating machine.

Description

Technical Field

[0001] The present invention belongs to the technical field of rotating structure testing, and in particular relates to a dynamic testing method for the clearance between a rotor and a stator. Background Art

[0002] Rotating machinery, such as aircraft engines and gas turbines, possesses complex structures, consisting of numerous high-speed rotating components and a variety of stationary components. Due to their high speeds and high temperatures, rotating components are subjected to both centrifugal and thermal loads, causing radial growth of the rotor during operation. Stationary components also experience significant thermal deformation in high-temperature environments, leading to unpredictable changes in the rotor-stator clearance, significantly impacting the operating efficiency and safety of the rotating machinery. Therefore, dynamic, real-time measurement of the rotor-stator clearance and understanding the radial deformation patterns of both rotors and stators are crucial for the design and development of rotating machinery.

[0003] Therefore, a dynamic testing method for the clearance between rotor and stator is proposed. Summary of the Invention

[0004] The present invention aims to provide a dynamic testing method for the clearance between a rotor and a stator, so as to solve or improve at least one of the above-mentioned technical problems.

[0005] In view of this, a first aspect of the present invention is to provide a dynamic testing method for the clearance between a rotor and a stator.

[0006] A first aspect of the present invention provides a dynamic testing method for the clearance between a rotor and a stator, comprising a first measuring portion having a measuring end abutting against a side wall of the stator and a second measuring portion corresponding to a side wall of the rotor, and comprising the following steps: S1, in a stationary state, using a wedge-shaped feeler gauge to measure the cold clearance between the rotor and the stator; S2, in a rotating state, using the second measuring portion to measure a change in the clearance between the rotor and the stator; S3, in a rotating state, using the first measuring portion to measure a radial deformation of the stator; S4, adding the cold clearance measured in the stationary state and the change in the clearance measured in the rotating state to obtain a real-time clearance between the rotor and the stator in the rotating state, and subtracting the radial deformation measured in the rotating state from the change in the clearance measured in the rotating state to obtain a real-time radial deformation of the rotor.

[0007] This invention provides a dynamic rotor-stator clearance testing method. Through contact measurement using a first measuring unit and non-contact measurement using a second measuring unit, this method enables full-process, real-time measurement of the rotor-stator radial clearance during component operation, supporting the design of rotor-stator clearances for rotating machinery. Furthermore, based on the contact and non-contact test data, the radial deformation of the rotor and stator can be calculated, supporting safety analysis of rotating machinery.

[0008] In addition, the technical solution provided by the embodiment of the present invention may also have the following additional technical features:

[0009] In any of the above technical solutions, the axis of the measuring end of the first measuring part points to the axis of the rotor and is perpendicular to the axis of the rotor; wherein the first measuring part is a rebound displacement sensor and the second measuring part is an optical fiber displacement sensor.

[0010] In this technical solution, the measuring end of the first measuring part is aligned with the axis of the rotor before measurement is performed, which can ensure that the detection angle and direction are correct, so that the measuring end can accurately measure the stator outer wall point radially corresponding to the rotor surface point.

[0011] In any of the above technical solutions, at least one of the first measuring part and the second measuring part is respectively provided along the circumference of the stator, and the step S1 includes: S101, fixing the rotor, inserting a wedge-shaped feeler gauge into the gap between the rotor and the stator, corresponding to the measuring end of the second measuring part along the radial direction of the rotor; S102, recording the degree of the wedge-shaped feeler gauge, and performing a reflective mark on the side wall of the rotor corresponding to the wedge-shaped feeler gauge.

[0012] In this technical solution, at least one of the first measuring part and the second measuring part is respectively provided along the circumference of the stator. When facing a stator and a rotor with poor manufacturing process, multi-point measurement can be adopted to ensure that a part is not too protruding or too concave relative to other parts of the circumference, causing distortion of the results.

[0013] When the rotor is fixed, a wedge-shaped feeler gauge is used to measure the gap between the rotor and the stator. This can obtain the measurement parameters in the cold state before the rotor is put into operation, and serve as the initial measurement data to provide a calculation and reference basis for subsequent dynamic measurement data.

[0014] When measuring with a wedge-shaped feeler gauge, the measuring end of the second measuring portion is aligned with the radial direction of the rotor, and a reflective mark is applied to the portion after measurement. This allows for continuous measurement of the same portion during subsequent rotor rotation measurements, thereby avoiding measurement at different circumferential positions and reducing measurement errors caused by manufacturing tolerances.

[0015] In any of the above technical solutions, a threaded hole is radially provided on the stator, and the measuring end of the second measuring part is sleeved with a tapered tube adapted to the threaded hole; wherein, the radial distance between the measuring end of the second measuring part and the inner wall of the stator in the threaded hole is 0 mm-0.5 mm.

[0016] In this technical solution, when the measuring end of the second measuring part is installed, a tapered tube is sleeved on the measuring end, the outer wall of which is screwed to the threaded hole and used for sealing. This can prevent the fluid between the stator and the rotor from leaking through the gap between the measuring end and the stator during measurement, causing uneven force on the rotor and polarization, which affects the measurement data.

[0017] When installing the measuring end of the second measuring part, a radial distance of 0mm-0.5mm is set between the end face of the measuring end facing the rotor and the inner wall of the stator to prevent the measuring end from protruding into the threaded hole of the stator and affecting and interfering with the fluid flow between the stator and the rotor; further, the end face of the measuring end facing the rotor is tangent to the internal arc surface of the stator.

[0018] In any of the above technical solutions, a photoelectric element corresponding to the reflective mark is provided, and the first measuring part and the second measuring part are connected respectively, and the step S2 includes: S201, starting the rotor to rotate, and when the photoelectric element is opposite to the reflective mark, the second measuring part starts to measure the change in the gap between the rotor and the stator; S202, repeating S201 to obtain the change in the gap between the rotor and the stator at different rotor temperatures.

[0019] In this technical solution, the reflective mark is sensed by a photoelectric element, and the first measuring part and the second measuring part connected thereto are activated to measure and read the degree, which can ensure that the first measuring part and the second measuring part measure the same point each time when the rotor rotates;

[0020] Whenever the reflective mark is opposite to the photoelectric element, the second measuring part performs measurement, and outputs the adjacent measurement data or the measurement data at a certain interval, which can reduce the subsequent calculation pressure and ensure the regularity of the measurement data for later analysis.

[0021] In any of the above technical solutions, the S2 also includes: S203, obtaining the real-time rotational speed of the rotor corresponding to each gap change, judging whether the real-time rotational speed is greater than the first-order critical speed and the second-order critical speed of the current rotor, if so, retaining the current gap change, otherwise deleting it; S204, obtaining the actual vibration frequency of the rotor and the phase corresponding to the reflective mark, performing linear filtering on the vibration frequency and separating the deviation introduced by the vibration from the gap change.

[0022] In this technical solution, due to the properties of the rotor itself, each rotor has a specific imbalance response when operating, which causes the data measured based on the rotor surface to fluctuate and be inaccurate. Therefore, eliminating the measurement interference of rotor vibration can ensure that multiple measurement degrees converge with the actual situation during centralized calculation, thereby reducing the overall error.

[0023] The linear filter is used to separate the deviation introduced by vibration from the measured gap change, which can make the result more accurate and stable, and ensure the accuracy of the final calculation.

[0024] In any of the above technical solutions, a synchronizer is provided between the first measuring part and the second measuring part, and the step of S3 includes: S301, when the second measuring part is measuring, the first measuring part is synchronously started to measure through the synchronizer to obtain the radial deformation of the stator; S302, S301 is repeated to obtain the radial deformation of the stator at different temperatures.

[0025] In this technical solution, a synchronizer is used to synchronize the measurement time points of the first measuring part and the second measuring part, ensuring that the two measurement results are measurement data of the same rotor temperature at the same time, avoiding time misalignment of the data.

[0026] In any of the above technical solutions, the intersection of the axes of the detection ends of the first measuring part and the second measuring part is located on the side wall surface of the rotor; or the axes of the detection ends of the first measuring part and the second measuring part are parallel, and the detection ends of the first measuring part and the second measuring part are arranged along the axial direction of the stator; or the intersection of the axes of the detection ends of the first measuring part and the second measuring part is located on the axis of the rotor.

[0027] In this technical solution, the intersection of the axes of the detection ends of the first measuring part and the second measuring part is located on the side wall surface of the rotor, and the axis of the measuring end of the first measuring part is directed to and perpendicular to the axis of the rotor. This ensures that the measurement points of the first measuring part and the second measuring part correspond along the radial direction of the rotor, further ensuring the uniformity of the measurement points.

[0028] The axes of the detection ends of the first measuring part and the second measuring part are parallel, and the detection ends of the first measuring part and the second measuring part are arranged along the axial direction of the stator, so that corresponding measurements can be performed along the axial direction, avoiding the influence of the manufacturing tolerance of the rotor and the stator in the circumferential direction;

[0029] The intersection of the axes of the detection ends of the first measuring part and the second measuring part is located on the axis of the rotor, so that when the first measuring part and the second measuring part are arranged along the circumference of the stator, the measuring directions can both be radial directions, so as to better measure the radial expansion of the stator and the rotor.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] Through combined contact and non-contact testing under laboratory conditions, the full-process, real-time measurement of rotor-stator radial clearance can be achieved during component operation, supporting the design of rotor-stator clearance for rotating machinery. Furthermore, based on contact and non-contact test data, the radial deformation of the rotor and stator can be identified, supporting rotating machinery safety analysis.

[0032] Additional aspects and advantages of embodiments according to the present invention will become apparent in the following description or may be learned through practice of embodiments according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings are only for purposes of illustrating particular embodiments and are not to be considered limiting of the invention.

[0034] Figure 1 Schematic diagram of the clearance measurement between the rotor and the stator in a stationary state of the present invention;

[0035] Figure 2 This is a schematic diagram of measuring the gap variation between the rotor and the stator in a rotating state according to the present invention.

[0036] in, Figure 1-2 The corresponding relationship between the reference numerals and component names is as follows:

[0037] 1 stator, 2 rotor, 3 wedge-shaped feeler gauge, 4 fiber optic displacement sensor, 5 rebound displacement sensor. DETAILED DESCRIPTION

[0038] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other.

[0039] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0040] See also Figure 1-2 The first aspect of the present invention provides a dynamic testing method for the clearance between a rotor and a stator, comprising the following steps:

[0041] Regarding the concentricity deviation during processing and assembly, since the concentricity deviation is usually the same in the static state and the rotating state, after the stator 1 and the rotor 2 are installed, the clearances at different equally spaced circumferential positions are measured in the static state, and the concentricity deviation can be obtained by calculation.

[0042] Step 1: In a stationary state, use a wedge-shaped feeler gauge 3 to measure the cold clearance c0 between the rotor 2 and the stator 1 in the initial state;

[0043] Furthermore, the test was repeated at different circumferential positions, and six measuring points were set at equal intervals along the inner wall of the stator 1 to obtain the circumferential distribution difference of the clearance between the rotor 2 and the stator 1 in the cold state.

[0044] Step 2: In a stationary state, install the non-contact displacement sensor on the stator 1. The installation method is to open a threaded hole in the stator 1, insert a tapered tube to seal and fix the non-contact displacement sensor, and ensure that there is no fluid leakage at the sensor connection. At the same time, the probe of the non-contact displacement sensor is flush and tangent to the inner wall of the stator 1 or radially away from the stator, and cannot protrude from the inner wall of the stator 1 to reduce interference with the internal flow field of the fluid machinery; the axial direction of the sensor is perpendicular to the axis of the rotor 2 and points to the axis of the rotor 2 to ensure that the measured deformation is the change in the radial gap between the rotor 2 and the stator 1;

[0045] Specifically, the non-contact displacement sensor adopts an optical fiber displacement sensor 4;

[0046] Specifically, the distance between the probe of the non-contact displacement sensor and the inner wall of the stator 1 is between 0 mm and 0.5 mm.

[0047] Step 3: In a stationary state, install a contact displacement sensor on the outer wall of the stator 1, with the axial direction of the contact displacement sensor perpendicular to the axis of the rotor 2, so that the measured deformation is the radial deformation of the stator 1;

[0048] Specifically, the contact displacement sensor adopts a rebound displacement sensor 5;

[0049] Step 4: In the working state, record the measurement result of the non-contact displacement sensor, which is the gap change Δc between the rotor 2 and the stator 1;

[0050] Furthermore, six measuring points are set at equal intervals along the circumferential direction of the outer wall of the stator 1 to reduce the influence of the circumferential asymmetry of the radial deformation of the stator 1 on the measurement results;

[0051] Furthermore, during the measurement process, a synchronizer is used to control the acquisition signal of the non-contact displacement sensor to ensure that the difference in the acquisition time of the non-contact displacement sensor at each measuring point is negligible relative to the acquisition frequency;

[0052] Furthermore, after obtaining the six synchronously collected gap variations, the gap variations of the complete circumference are fitted according to the spatial position (circumferential angle), thereby obtaining the spatial distribution position of the gap variations along the circumferential direction at the current moment;

[0053] Furthermore, it is approximately believed that the vibration deviation has certain periodic characteristics, and the vibration frequency is much lower than the data acquisition frequency. Therefore, the actual vibration frequency of the rotor 2 is measured by a vibration sensor and is known by the data acquisition system. After filtering the vibration frequency, the deviation introduced by the vibration can be separated. For a certain measuring point, the deviation introduced by the vibration of the rotor 2 presents a sinusoidal fluctuation characteristic, that is, e=Asin(ωt+φ), where A is the amplitude of the deviation, ω is the fluctuation frequency of the deviation, t is time, and φ is the initial phase of the deviation. For different measuring points, the fluctuation amplitude and fluctuation frequency of the deviation are the same, but the initial phase is different because the phase is related to the circumferential position;

[0054] Furthermore, the change in the rotor-to-stationary clearance after eliminating the vibration deviation is Δc' = Δc-e;

[0055] Step 5: Using the cold clearance c0 between the rotor 2 and the stator 1 in the initial state and the rotor-to-stator clearance change Δc' in the working state, calculate the real-time clearance c between the rotor 2 and the stator 1, that is, c = c0 + Δc';

[0056] Step 6: Under working condition, record the measurement results of the contact displacement sensor, i.e. the radial deformation Δc of the stationary component s ;

[0057] Step 7: Use the gap change Δc' between rotor 2 and stator 1 and the radial deformation Δc of stator 1 s The radial deformation Δc of rotor 2 is calculated r , that is, Δc r =Δc s -Δc'.

[0058] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0059] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A dynamic testing method for the clearance between a rotor and a stator, characterized in that: The first measuring portion with a measuring end abutting against the stator side wall and the second measuring portion with a measuring end corresponding to the rotor side wall are respectively provided, comprising the following steps: S1, in the static state, use a wedge-shaped feeler gauge to measure the cold clearance between the rotor and stator; S2, in the rotating state, using the second measuring part to measure the gap change between the rotor and the stator; S3, in the rotating state, using the first measuring part to measure the radial deformation of the stator; S4, adding the cold clearance measured in the static state and the clearance change measured in the rotating state to obtain the real-time clearance between the rotor and the stator in the rotating state, and subtracting the radial deformation measured in the rotating state from the clearance change measured in the rotating state to obtain the real-time radial deformation of the rotor; At least one of the first measuring portion and the second measuring portion is respectively provided along the circumference of the stator, and the step S1 includes: S101, fixing the rotor, inserting a wedge-shaped feeler gauge into the gap between the rotor and the stator, aligned with the measuring end of the second measuring portion along the radial direction of the rotor; S102, recording the reading of the wedge-shaped feeler gauge and performing a reflective mark on the side wall of the rotor corresponding to the wedge-shaped feeler gauge; A photoelectric element is provided corresponding to the reflective mark and connected to the first measuring part and the second measuring part respectively, and the step S2 includes: S201, starting the rotor to rotate, and when the photoelectric element is opposite to the reflective mark, the second measuring unit starts to measure the change in the gap between the rotor and the stator; S202, repeating S201 to obtain a change in the gap between the rotor and the stator at different rotor temperatures; S203, obtaining the real-time rotor speed corresponding to each gap change, and determining whether the real-time speed is greater than the first-order critical speed and the second-order critical speed of the current rotor. If so, retain the current gap change; otherwise, delete it; S204 , obtaining the actual vibration frequency of the rotor and the phase corresponding to the reflective mark, performing linear filtering on the vibration frequency, and extracting the deviation introduced by the vibration from the gap variation.

2. The dynamic testing method of the rotor and stator clearance according to claim 1, characterized in that: The axis of the measuring end of the first measuring portion points to the axis of the rotor and is perpendicular to the axis of the rotor; Wherein, the first measuring part is a rebound displacement sensor, and the second measuring part is an optical fiber displacement sensor.

3. The dynamic testing method of the rotor and stator clearance according to claim 1, characterized in that: The stator is provided with a threaded hole in the radial direction, and the measuring end of the second measuring part is provided with a tapered tube adapted to the threaded hole; Wherein, the radial distance between the measuring end of the second measuring part in the threaded hole and the inner wall of the stator is 0 mm-0.5 mm.

4. The dynamic testing method of the rotor and stator clearance according to claim 1, characterized in that: Setting a synchronizer with the first measuring unit and the second measuring unit, and the step S3 includes: S301, when the second measuring unit is measuring, the first measuring unit is synchronously started to measure the degree through the synchronizer to obtain the radial deformation of the stator; S302, repeat S301 to obtain the radial deformation of the stator at different temperatures.

5. The dynamic testing method of the rotor and stator clearance according to claim 2, characterized in that: The intersection of the axes of the detection ends of the first measuring portion and the second measuring portion is located on the side wall surface of the rotor; or The axes of the detection ends of the first measuring part and the second measuring part are parallel, and the detection ends of the first measuring part and the second measuring part are arranged along the axis direction of the stator; or The intersection of the axes of the detection ends of the first measuring portion and the second measuring portion is located on the axis of the rotor.

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