System for testing axial movement of rotor in small space

Abstract

The invention discloses a system for testing axial movement of a rotor in a small space, and belongs to the technical field of dynamic testing of industrial gearboxes. According to the invention, the problems of poor real-time performance and diagnosis lag caused by intermittent measurement, inconvenient installation and lack of dynamic analysis in the existing rotor axial movement detection method are solved. The system comprises an S-shaped support adjustably installed on a rotor protection cover, an eddy current sensor installed on the support and provided with a probe facing a rotor shaft shoulder, a front-end device connected with the sensor through an extension line, a multi-channel synchronous signal acquisition instrument connected with the front-end device, and an upper computer in communication connection with the acquisition instrument. And the upper computer identifies the fault characteristic frequency related to the axial movement by performing time domain analysis, Fourier transform frequency analysis and order analysis on the displacement data, and generates an early warning signal. According to the invention, high-precision real-time monitoring and dynamic fault diagnosis of axial movement of the rotor are realized, and the method is suitable for on-line health management of the industrial gearbox rotor.

Description

Technical Field

[0001] This invention relates to the field of dynamic testing technology for industrial gearboxes, and more specifically to a test system for axial movement of rotors in small spaces. Background Technology

[0002] Axial runout of rotors is a common fault during the operation of rotating machinery and industrial gearboxes. Its causes are complex and varied, but can be mainly summarized as follows: 1. Design and manufacturing defects, such as unreasonable rotor structure, uneven material distribution, or coupling installation deviations; 2. Abnormal operating conditions, including load fluctuations, uneven rotor heating leading to thermal deformation, and consequently, loose bearings, excessive clearance, and poor lubrication; 3. Mechanical wear and fatigue, i.e., after long-term operation, wear on gear meshing surfaces, thrust discs, or bearings can lead to increased axial clearance, causing the rotor to lose its effective axial positioning function.

[0003] The hazards caused by rotor axial movement are multifaceted, mainly including: 1. Equipment damage risk, which may lead to serious accidents such as broken gear teeth and burnt bearings; 2. Increased vibration and noise, as axial movement can excite power frequency and harmonic vibrations, resulting in decreased unit operating stability and abnormal noise; 3. Reduced transmission efficiency, as poor gear meshing or uneven bearing load leads to decreased transmission efficiency and increased energy consumption.

[0004] Currently, in industrial settings, the most common method for detecting gearbox shaft runout is manual measurement using a dial indicator. This method is typically used during equipment shutdown inspections, where the rotor's total runout is measured by manual rotation. It is widely applied for accuracy verification during reassembly or as a means of checking bearing top clearance, bearing load distribution, and coupling alignment during routine maintenance. However, this traditional method has significant drawbacks: First, its detection is intermittent, failing to acquire the dynamic runout of the shaft during operation in real time and accurately, resulting in a severe lag in problem analysis and diagnosis; second, conventional sensors and their associated S-shaped brackets are often large in size, making it difficult to adapt to the compact internal space of the gearbox cavity, leading to difficulties in measuring point placement.

[0005] In summary, existing technologies have limitations in terms of real-time performance, spatial adaptability, and analytical depth. Therefore, there is an urgent need for a testing system that can be installed in confined spaces and simultaneously possesses high-precision displacement measurement and dynamic analysis capabilities to meet the requirements for real-time monitoring and intelligent diagnosis of rotor axial movement during high-speed operation of industrial gearboxes. Summary of the Invention

[0006] The purpose of this invention is to solve the problems of poor real-time performance and diagnostic lag caused by intermittent measurement, inconvenient installation and lack of dynamic analysis in existing rotor axial movement detection methods, and to provide a rotor axial movement testing system for small spaces.

[0007] The technical solution of this invention is:

[0008] This invention provides a system for testing the axial movement of rotors in small spaces, comprising:

[0009] The S-shaped bracket 3 is adjustablely and fixedly installed on the rotor protective cover 2;

[0010] An eddy current sensor 7 is mounted on the S-shaped bracket 3, with its probe end facing the rotor shaft shoulder 1, and is used to measure the rotor axial displacement in real time.

[0011] The preamplifier is connected to the output terminal of the eddy current sensor 7 via an extension line, and is used to amplify, filter and linearize the electrical signal output by the eddy current sensor 7.

[0012] A multi-channel synchronous signal acquisition instrument, connected to the output of the preamplifier, is used for synchronous sampling and analog-to-digital conversion of the conditioned electrical signal; and

[0013] The host computer is connected to the multi-channel synchronous signal acquisition instrument. By performing time-domain analysis, Fourier transform frequency analysis, and order analysis on the displacement data measured by the eddy current sensor 7, it identifies and extracts fault characteristic frequencies related to axial movement, and then generates an early warning signal.

[0014] Furthermore, the eddy current sensor 7 is a side-outlet type sensor with a probe diameter of no more than 15mm.

[0015] Furthermore, the linear range of the eddy current sensor 7 is not less than 4 mm, and the resolution is not less than 1 μm.

[0016] Furthermore, the S-shaped bracket 3 is provided with a mounting part for mounting the eddy current sensor 7, the mounting part including at least two bolt holes, and the S-shaped bracket 3 is fixed to the rotor protective cover 2 by at least two bolts.

[0017] Furthermore, the bolt hole for mounting the eddy current sensor 7 is an oblong hole or a waist-shaped hole, and the length direction of the oblong hole or waist-shaped hole is parallel to the axial direction of the rotor.

[0018] Furthermore, bolt washers 5 are provided at the bolt connection between the S-shaped bracket 3 and the rotor protective cover 2. The initial static gap between the probe of the eddy current sensor 7 and the rotor shaft shoulder 1 can be adjusted by adjusting the number and / or thickness of the bolt washers 5.

[0019] Furthermore, the initial static gap between the probe of the eddy current sensor 7 and the rotor shaft shoulder 1 is 2 mm.

[0020] Furthermore, the sampling frequency of the multi-channel synchronous signal acquisition instrument is not less than 51.2kHz, and it has a built-in anti-aliasing filter with a cutoff frequency of not less than 20kHz.

[0021] Furthermore, the host computer includes an early warning module, which is used to trigger an alarm signal or a shutdown signal when the 1 / 2X, 1X or 2X frequency components in the vibration signal exceed a preset threshold.

[0022] Furthermore, the outline of the S-shaped bracket 3 is adapted to the mounting surface of the rotor protective cover 2 so that the entire test system can be accommodated in the compact cavity of the gearbox.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. The system of this invention integrates an eddy current sensor 7, an adjustable S-shaped bracket 3, and dynamic signal analysis technology to achieve continuous measurement of rotor axial displacement, identification of fault characteristic frequencies, and early warning of potential faults. It is suitable for online health management of rotors in industrial gearboxes and fundamentally solves the problems of poor real-time performance and diagnostic lag caused by intermittent measurement and lack of dynamic analysis in existing technologies.

[0025] 2. The system of the present invention adopts a side-outlet eddy current sensor 7 with a probe diameter of no more than 15mm and an S-shaped bracket 3 that is adapted to the contour of the rotor protective cover 2, so that the entire test system can be accommodated in the compact cavity of the gearbox, effectively solving the problem of difficult measurement point arrangement of conventional sensors and S-shaped brackets in a narrow space.

[0026] 3. By adjusting the number and thickness of the bolt washers 5 between the S-shaped bracket 3 and the rotor protective cover 2, the initial static gap (e.g., 2mm) between the probe of the eddy current sensor 7 and the rotor shaft shoulder 1 can be precisely adjusted, ensuring that the sensor works in the optimal linear measurement range (linear range ≥ 4mm, resolution ≥ 1μm), thereby ensuring the realization of high-precision displacement measurement.

[0027] 4. The system of this invention utilizes a multi-channel synchronous signal acquisition instrument with a sampling frequency ≥ 51.2 kHz and a built-in anti-aliasing filter (cutoff frequency ≥ 20 kHz), which can completely capture high-frequency oscillation signals (such as the 2X component of gear meshing frequency). Then, through time domain, Fourier transform frequency and order analysis by the host computer, fault characteristic frequencies such as 1 / 2X, 1X, and 2X can be accurately extracted, realizing accurate judgment and early warning of fault sources such as bearing loosening and thermal deformation.

[0028] 5. The system of this invention can generate a deterioration curve of rotor axial movement by storing operating data in the host computer for a long time and performing trend analysis, quantifying its deterioration law, providing solid data support for predictive maintenance of equipment, extending equipment service life and avoiding sudden downtime. Attached Figure Description

[0029] Figure 1 This is a schematic diagram showing the installation position of the sensor of the present invention on the rotor protective cover;

[0030] Figure 2 This is a schematic diagram of the hole distribution of the S-shaped bracket of the present invention;

[0031] Figure 3 This is a system architecture connection diagram of the present invention;

[0032] Figure 4 This is a schematic diagram of the overall structure of the rotor axial movement test system of the present invention.

[0033] In the diagram: 1-rotor shoulder, 2-rotor protective cover, 3-S-shaped bracket, 5-bolt washer, 7-eddy current sensor. Detailed Implementation

[0034] Specific implementation method one: Combining Figures 1 to 4 This embodiment of the invention provides a rotor axial movement testing system for small spaces, comprising:

[0035] The S-shaped bracket 3 is adjustablely and fixedly installed on the rotor protective cover 2;

[0036] An eddy current sensor 7 is mounted on the S-shaped bracket 3, with its probe end facing the rotor shaft shoulder 1, and is used to measure the rotor axial displacement in real time.

[0037] The preamplifier is connected to the output terminal of the eddy current sensor 7 via an extension line, and is used to amplify, filter and linearize the electrical signal output by the eddy current sensor 7.

[0038] A multi-channel synchronous signal acquisition instrument is connected to the output of the preamplifier and is used to synchronously sample and convert the conditioned electrical signal into an analog-to-digital signal. The host computer is connected to the multi-channel synchronous signal acquisition instrument. By performing time-domain analysis, Fourier transform frequency analysis, and order analysis on the displacement data, it identifies and extracts fault characteristic frequencies related to axial movement, and then generates early warning signals.

[0039] Specific Implementation Method Two: Combining Figures 1 to 4In this embodiment, the eddy current sensor 7 is a side-outlet sensor with a probe diameter of no more than 15mm. This design effectively avoids wiring interference with surrounding components within a compact space, and the probe diameter of no more than 15mm ensures its installation feasibility in a small cavity. Other components and connections are the same as in Specific Embodiment One.

[0040] Specific implementation method three: Combining Figures 1 to 4 In this embodiment, the eddy current sensor 7 has a linear range of not less than 4 mm and a resolution of not less than 1 μm. This configuration, with a linear range of not less than 4 mm and a resolution of not less than 1 μm, ensures that the system can accurately capture minute axial displacement changes during rotor operation, meeting the requirements for high-precision dynamic displacement measurement. Other components and connections are the same as in specific embodiments one or two.

[0041] Specific implementation method four: Combination Figures 1 to 4 In this embodiment, the S-shaped bracket 3 is provided with a mounting portion for mounting the eddy current sensor 7. This mounting portion includes at least two bolt holes, and the S-shaped bracket 3 is fixed to the rotor protective cover 2 by at least two bolts. This arrangement, with the sensor mounted through at least two bolt holes and the S-shaped bracket 3 fixed to the rotor protective cover 2 by at least two bolts, ensures the installation rigidity and stability of the entire test structure under high-speed vibration conditions. Other components and connections are the same as in specific embodiments one, two, or three.

[0042] Specific Implementation Method Five: Combining Figures 1 to 4 In this embodiment, the bolt holes for mounting the eddy current sensor 7 are oblong or slotted holes, with the length direction of the oblong or slotted hole parallel to the axial direction of the rotor. This design provides fine-tuning space for the axial position of the eddy current sensor 7, allowing for convenient initial positioning by sliding along the axial direction, thus enhancing installation flexibility and fault tolerance. Other components and connections are the same as in specific embodiments one, two, three, or four.

[0043] Specific Implementation Method Six: Combination Figures 1 to 4 In this embodiment, bolt washers 5 are provided at the bolt connection between the S-shaped bracket 3 and the rotor protective cover 2. By adjusting the number and / or thickness of the bolt washers 5, the initial static clearance between the eddy current sensor 7 probe and the rotor shoulder 1 can be adjusted. This configuration allows for precise, stepless adjustment of the initial static clearance through the simple mechanical operation of adding, removing, or replacing the bolt washers 5; the method is simple and reliable. Other components and connections are the same as in specific embodiments one, two, three, four, or five.

[0044] Specific implementation method seven: Combination Figures 1 to 4 In this embodiment, the initial static gap between the probe of the eddy current sensor 7 and the rotor shoulder 1 is 2mm. This setting, with an initial static gap of 2mm (taking a sensor linear range of 4mm as an example), allows the sensor to operate near the center of its linear range, providing the optimal dynamic range for bidirectional displacement measurement, while simultaneously preventing collision between the probe and the shoulder. Other components and connections are the same as in specific embodiments one, two, three, four, five, or six.

[0045] Specific implementation method eight: Combination Figures 1 to 4 This embodiment describes a multi-channel synchronous signal acquisition instrument with a sampling frequency of no less than 51.2 kHz and a built-in anti-aliasing filter with a cutoff frequency of no less than 20 kHz. This configuration, along with the high sampling rate and anti-aliasing filter, ensures that high-frequency dynamic signals (such as gear meshing frequencies and their harmonics) can be acquired completely and without distortion, laying a data foundation for subsequent accurate spectrum analysis. Other components and connections are the same as in specific embodiments one, two, three, four, five, six, or seven.

[0046] Specific Implementation Method Nine: Combining Figures 1 to 4 This embodiment describes a host computer that includes an early warning module. This module triggers an alarm or shutdown signal when the 1 / 2X, 1X, or 2X frequency components in the vibration signal exceed a preset threshold. This configuration allows for automatic monitoring of the amplitude of specific fault characteristic frequency components (1 / 2X, 1X, 2X) by a software module, comparing them with preset thresholds. This enables automatic fault identification and grading (alarm / shutdown) early warning, significantly improving the safety and intelligence of equipment operation. Other components and connections are the same as in specific embodiments one, two, three, four, five, six, seven, or eight.

[0047] Specific Implementation Method Ten: Combining Figures 1 to 4 In this embodiment, the S-shaped bracket 3 is designed to fit the mounting surface of the rotor protective cover 2, allowing the entire testing system to be accommodated within the compact cavity of the gearbox. This adaptable design of the S-shaped bracket 3 is key to its ability to fit into confined spaces, directly achieving the system's core purpose of being used in small spaces. Other components and connections are the same as in specific embodiments one, two, three, four, five, six, seven, eight, or nine.

[0048] Working principle

[0049] Combination Figures 1 to 4 This invention explains the working principle of the rotor axial movement testing system in a small space:

[0050] First, the S-shaped bracket 3 is adjustablely fixed to the rotor protective cover 2 using bolts and bolt washers 5, and the initial static gap (e.g., 2 mm) between the probe of the eddy current sensor 7 and the rotor shoulder 1 is precisely set by adjusting the shims (5). When the rotor is running, its axial movement causes a change in the gap between it and the probe of the eddy current sensor 7. This change is sensed by the eddy current sensor 7 in real time and converted into an electrical signal. This signal is transmitted to the preamplifier via an extension line for amplification, filtering, and linearization. Subsequently, the processed standard signal is sampled and converted from analog to digital by a multi-channel synchronous signal acquisition instrument at high speed. Finally, the digitized displacement data is uploaded to the host computer. The host computer software performs real-time time-domain analysis, Fourier transform frequency analysis, and order analysis on the data. By identifying the amplitude changes of characteristic frequencies such as 1 / 2X (which may indicate bearing loosening), 1X (power frequency imbalance), and 2X (gear meshing frequency component) in the vibration signal, the source and severity of the axial movement fault are determined. Once the characteristic frequency component exceeds the preset threshold, the system immediately triggers an alarm or shutdown signal to achieve early warning. Meanwhile, the system stores data for a long time and generates degradation curves through trend analysis, providing a basis for predictive maintenance decisions.

[0051] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A test system for axial movement of rotors in small spaces, characterized in that, include: The S-shaped bracket (3) is adjustablely fixed on the rotor protective cover (2); An eddy current sensor (7) is mounted on the S-shaped bracket (3), with its probe end facing the rotor shoulder (1), for real-time measurement of rotor axial displacement; The preamplifier is connected to the output end of the eddy current sensor (7) via an extension line and is used to amplify, filter and linearize the electrical signal output by the eddy current sensor (7). A multi-channel synchronous signal acquisition instrument is connected to the output of the preamplifier and is used to synchronously sample and convert the conditioned electrical signal into an analog-to-digital signal. as well as The host computer is connected to the multi-channel synchronous signal acquisition instrument. By performing time-domain analysis, Fourier transform frequency analysis, and order analysis on the displacement data, it identifies and extracts fault characteristic frequencies related to axial movement, and then generates early warning signals.

2. The rotor axial movement testing system for small spaces according to claim 1, characterized in that, The eddy current sensor (7) is a side-outlet type sensor with a probe diameter of no more than 15 mm.

3. A rotor axial movement testing system for small spaces according to claim 1 or 2, characterized in that, The linear range of the eddy current sensor (7) is not less than 4 mm and the resolution is not less than 1 μm.

4. The rotor axial movement testing system for small spaces according to claim 3, characterized in that, The S-shaped bracket (3) is provided with a mounting part for mounting the eddy current sensor (7), the mounting part including at least two bolt holes, and the S-shaped bracket (3) is fixed to the rotor protective cover (2) by at least two bolts.

5. A rotor axial movement testing system for small spaces according to claim 4, characterized in that, The bolt holes for mounting the eddy current sensor (7) are oblong or waist-shaped holes, and the length direction of the oblong or waist-shaped hole is parallel to the axial direction of the rotor.

6. A rotor axial movement testing system for small spaces according to claim 5, characterized in that, Bolt washers (5) are provided at the bolt connection between the S-shaped bracket (3) and the rotor protective cover (2). The initial static gap between the probe of the eddy current sensor (7) and the rotor shoulder (1) can be adjusted by adjusting the number and / or thickness of the bolt washers (5).

7. A rotor axial movement testing system for small spaces according to claim 6, characterized in that, The initial static gap between the probe of the eddy current sensor (7) and the rotor shoulder (1) is 2 mm.

8. The rotor axial movement testing system for small spaces according to claim 1, characterized in that, The multi-channel synchronous signal acquisition instrument has a sampling frequency of not less than 51.2kHz and a built-in anti-aliasing filter with a cutoff frequency of not less than 20kHz.

9. A rotor axial movement testing system for small spaces according to claim 1, characterized in that, The host computer includes an early warning module, which is used to trigger an alarm signal or a shutdown signal when the 1 / 2X, 1X or 2X frequency components in the vibration signal exceed a preset threshold.

10. A rotor axial movement testing system for small spaces according to claim 1, characterized in that, The outline of the S-shaped bracket (3) is adapted to the mounting surface of the rotor protective cover (2) so that the entire test system can be accommodated in the compact cavity of the gearbox.

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