Complete machine vibration verification method

Abstract

The invention belongs to the technical field of vibration monitoring, and particularly relates to a whole machine vibration verification method. Comprising the steps of installing a vibration original signal acquisition device to obtain an original signal of a measurement point A; and respectively carrying out vibration time domain and spectrum analysis on the original signal of the A measuring point to obtain an analysis result, and verifying whether vibration abnormity occurs according to the analysis result. The mechanical state information contained in the vibration signals is deeply excavated by non-intrusive acquisition of the original vibration signals of the A measuring point when the engine runs and fusion of time domain analysis and frequency domain analysis means. Under the condition that the original structure of the engine is not damaged, the engine vibration signal of the measuring point is measured in real time, and the signal is analyzed and judged. The troubleshooting waiting time is shortened, and reliable guarantee is provided for product delivery; the structure is stable, the use is convenient, the maintenance is simple, and the troubleshooting and use cost is low.

Description

Technical Field

[0001] This invention belongs to the field of vibration monitoring technology, and specifically relates to a method for verifying the vibration of an entire machine. Background Technology

[0002] In the development and production of aero-engines and industrial gas turbines, engine testing is a crucial step, used to comprehensively evaluate the engine's performance, durability, and safety. Bench testing, which simulates real-world operating conditions on a dedicated test bench, is standard industry practice. Vibration monitoring plays a critical role in this process because engine vibration levels directly reflect its mechanical condition; excessive vibration can lead to component fatigue or failure. Idle speed, the engine's low-power operating mode, is a common testing condition used to check stability at low speeds. Vibration sensors are deployed at multiple locations on the engine to collect vibration amplitude data (in μm) in real time and compare it with preset limits to ensure operational safety. This technology is widely used in aerospace, energy, and automotive fields, helping engineers identify potential problems promptly and ensuring equipment reliability.

[0003] Although vibration monitoring systems are maturely applied in engine testing, some challenging problems still arise in practical operation. Taking a certain type of engine as an example, during bench testing, over 50% of the engine exhibited abnormal fluctuations in vibration values ​​at the onboard measuring point A at idle speed. The vibration amplitude randomly fluctuated between 10μm and 70μm, sometimes even exceeding vibration limits. Therefore, monitoring the engine's operation was solely based on vibration values. This type of engine has seven measuring points: A, B, C, D, B1, C1, and D1. These seven points all use a narrow-bandwidth speed tracking method to measure vibration values ​​at the first harmonic of the engine speed, monitoring the overall engine vibration. Vibration sensors at points B and B1 are mounted on the same vibration measurement bracket. Points C, C1, D, and D1 are on the same cross-section, with C and C1 adjacent to each other, and D and D1 adjacent to each other. During engine operation, only measuring point A exhibited abnormalities or even exceeded limits, while other measuring points remained far below the limits. Furthermore, the sensor at this measuring point was installed inside the engine during assembly and cannot be disassembled, replaced, or inspected on a test bench. The raw vibration values ​​measured at measuring points A, C, and C1 are acceleration values, which need to be converted into displacement values ​​after double integration for monitoring. However, only the vibration value at measuring point A fluctuated significantly and even exceeded limits during low-speed operation; while the vibration value at this measuring point was relatively small or even negligible during high-speed engine operation. This is inconsistent with engine principles and requires verification. However, the sensor at this measuring point was installed inside the engine during assembly and cannot be disassembled, replaced, or inspected on a test bench. Summary of the Invention

[0004] The purpose of this invention is to provide a whole-machine vibration verification method to solve the technical problem in the prior art that it is impossible to verify whether there is an abnormality at measuring point A inside the engine without disassembling the engine.

[0005] To achieve the above objectives, the present invention employs the following technical solution: A method for verifying vibration of an entire machine includes: Install a vibration raw signal acquisition device to obtain the raw signal at measurement point A; The original signal at measurement point A was subjected to vibration time-domain and spectral analysis to obtain the analysis results. The analysis results were then used to verify whether vibration abnormalities had occurred.

[0006] Preferably, the original signal at measurement point A is subjected to vibration time-domain and spectral analysis to obtain analysis results. Verification of whether vibration anomalies have occurred is based on the analysis results, specifically including: Vibration time-domain analysis is performed on the original signal of measuring point A. If measuring point A only jumps in the slow state and the amplitude is within the abnormal threshold range, and there is no jumping in other states and the amplitude is within the small amplitude threshold, then the analysis result is that there is an abnormal signal in the slow state, which causes the vibration amplitude to jump. Spectral analysis of the abnormal signal reveals that if a low-frequency signal of 0-20 Hz is present, the abnormality is caused by interference; otherwise, the abnormality is attributed to engine vibration.

[0007] Preferably, the abnormal threshold range is when the vibration amplitude randomly fluctuates between 10μm and 70μm, or exceeds the limit of 80μm.

[0008] Preferably, the small amplitude threshold is a vibration amplitude of no more than 20 μm.

[0009] Preferably, after installing the vibration original signal acquisition device, the static connection of the device is first verified, and a power-on check is performed. After confirming that there are no errors, the engine test run is started to obtain the voltage signal at measurement point A.

[0010] Preferably, the vibration raw signal acquisition device includes: a dedicated adapter plug for measuring point A, which is plugged into the engine socket; a charge amplifier connected to the dedicated adapter plug for measuring point A; a data acquisition system connected to the charge amplifier; and a host computer connected to the data acquisition system.

[0011] Preferably, the A-point dedicated adapter includes a housing with signal + and signal - on it, which are used for testing and transmitting charge signals after connection.

[0012] Preferably, the dedicated adapter plug for measuring point A transmits the charge signal to the charge amplifier in the test bench control room via a low-noise shielded cable on the test bench.

[0013] Preferably, the charge amplifier transmits the voltage signal to the data acquisition system via a double-ended BNC line.

[0014] Preferably, the data acquisition system transmits data to the host computer via a data transmission network cable.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This application directly acquires the original signal from measurement point A by installing a vibration raw signal acquisition device, and further performs vibration time-domain and spectrum analysis. This method can collect and analyze multi-dimensional information, including vibration characteristics, in real time while continuously disassembling the original engine structure, thus overcoming the limitation of traditional airborne testing systems that can only provide a single vibration amplitude. This technical approach significantly enhances the accuracy and timeliness of judging abnormal engine vibration states, effectively shortens the fault diagnosis cycle, and reduces the delivery risk caused by diagnostic delays. At the same time, due to its stable structure and simple operation and maintenance, it not only improves the efficiency of overall engine vibration verification, but also significantly saves troubleshooting costs and resource investment, providing a reliable and economical technical guarantee for product delivery. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the method flow according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the connection of the vibration raw signal acquisition device according to an embodiment of the present invention.

[0018] Among them: 1- A-Specific adapter plug for measuring point A; 2-Low noise shielded cable for the test bench; 3-Charge amplifier; 4-Double-ended BNC cable; 5-Data acquisition system; 6-Host computer. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0024] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0025] The present invention will now be described in further detail with reference to the accompanying drawings: See Figure 1 This application discloses a method for verifying vibration of an entire machine, including: S1: Install the vibration raw signal acquisition device to obtain the raw signal of measuring point A; S2: Perform vibration time-domain and spectrum analysis on the original signal at measurement point A to obtain the analysis results, and verify whether vibration abnormality has occurred based on the analysis results.

[0026] This invention acquires the raw vibration signal from measuring point A during engine operation non-invasively, and integrates time-domain and frequency-domain analysis methods to deeply mine the mechanical state information contained in the vibration signal. In time-domain analysis, the changes in vibration amplitude, waveform characteristics, and impact components over time are observed to identify instantaneous anomalies or periodic fluctuations. In frequency-domain analysis, a Fast Fourier Transform (FFT) is used to convert the time-domain signal into a frequency-domain signal, thereby extracting the vibration energy distribution of different frequency components. Since the vibration value at measuring point A is directly acquired and displayed by the engine's onboard testing system, only the vibration amplitude is available, without related vibration characteristic information. This invention enables real-time measurement of the engine vibration signal at this measuring point without damaging the original engine structure, allowing for signal analysis and judgment. This reduces troubleshooting waiting time, providing a reliable guarantee for product delivery; the structure is stable, easy to use, simple to maintain, and has low troubleshooting and operating costs.

[0027] In some embodiments, performing vibration time-domain and spectral analysis on the original signal at measurement point A to obtain analysis results, and verifying whether vibration abnormality has occurred based on the analysis results, specifically includes: Vibration time-domain analysis is performed on the original signal of measuring point A. If measuring point A only jumps in the slow state and the amplitude is within the abnormal threshold range, and there is no jumping in other states and the amplitude is within the small amplitude threshold, then the analysis result is that there is an abnormal signal in the slow state, which causes the vibration amplitude to jump. Spectral analysis of the abnormal signal revealed that the presence of a low-frequency signal (0-20 Hz) indicated interference, while the absence of such a signal indicated abnormal engine vibration. This approach achieved greater precision and efficiency in fault diagnosis. The ambiguous alarm of "abnormality" was successfully refined into a precise diagnostic conclusion specifying "the condition and cause of the abnormality," significantly reducing unnecessary disassembly and inspection caused by misinterpreting external interference as engine failure. This not only significantly shortened the troubleshooting process, directly reducing maintenance time and labor costs, but also reduced over-reliance on the personal experience of diagnostic personnel, making vibration verification more standardized and reliable. Ultimately, this provided strong decision support for rapid and accurate assessment of engine condition, effectively ensuring product delivery schedules and operational safety. In some embodiments, the abnormal threshold range is when the vibration amplitude randomly fluctuates between 10μm and 70μm, or exceeds the limit of 80μm.

[0028] In some embodiments, the small amplitude threshold is a vibration amplitude of no more than 20 μm.

[0029] In some embodiments, after installing the vibration raw signal acquisition device, the static connection of the device is first verified, followed by a power-on check. Once confirmed to be correct, the engine test run begins to obtain the voltage signal at measurement point A. By performing static connection verification and power-on checks on the signal acquisition device before the engine's actual operation, a "known good" baseline state is essentially established at the starting point of the test link. This follows the systems engineering approach of "first eliminating measurement system faults, then diagnosing abnormalities in the tested object," ensuring that the subsequently acquired voltage signal at measurement point A accurately reflects the engine's vibration state, rather than being a false signal introduced by external factors such as loose sensor connections, broken circuits, or abnormal power supply.

[0030] In some embodiments, see Figure 2 The vibration raw signal acquisition device includes: a dedicated adapter plug 1 for measuring point A, which is plugged into the engine socket; a charge amplifier 3 connected to the adapter plug 1; a data acquisition system 5 connected to the charge amplifier 3; and a host computer connected to the data acquisition system 5. The dedicated adapter plug enables non-destructive connection with the engine's original test interface, forming a non-intrusive signal acquisition channel. The charge signal generated by the piezoelectric sensor is amplified and converted before being received and processed by the host computer. This process fully preserves the original characteristics of the vibration signal, laying a solid foundation for subsequent accurate analysis. This invention is used during engine testing. If the engine's vibration value fluctuates significantly at idle, this device is used to perform real-time testing and analysis of the engine's vibration signal, determining the engine's condition and verifying whether the vibration is caused by the engine itself or other interference signals, thereby ensuring the engine's operational safety.

[0031] In some embodiments, the A-point dedicated adapter 1 includes a housing with signal + and signal - provided on the housing, which are used for testing and transmitting charge signals after connection.

[0032] In some embodiments, the A-point dedicated adapter 1 transmits the charge signal to the charge amplifier 3 in the test bench control room via the bench low-noise shielded cable 2.

[0033] In some embodiments, the charge amplifier 3 transmits the voltage signal to the data acquisition system 5 via a double-ended BNC line 4.

[0034] In some embodiments, the data acquisition system 5 transmits data to the host computer via a data transmission network cable 6.

[0035] This device allows for real-time analysis of vibration signals, eliminating engine body vibration, identifying the cause of large fluctuations at idle, and preventing the engine from failing normal testing and delivery due to misjudgment of excessive vibration.

[0036]

Example 1

[0037] 1. Connection of the vibration raw signal acquisition device Disconnect the plug and socket from their original positions at the engine end. Use the A-point dedicated adapter plug to connect to the engine socket. The plug has signal +, signal -, and housing respectively. After connection, it can test and transmit charge signals. The charge signals are transmitted to the charge amplifier in the test bench control room through the low-noise shielded cable of the test bench. The charge amplifier then converts the signal into a voltage signal, which is then collected by the data acquisition system and software to collect the original vibration signal.

[0038] 2. Operational testing of the vibration raw signal acquisition device After the static connection of the vibration raw signal acquisition device is completed, power it on for inspection. After confirming that there are no errors, conduct engine test run and collect the vibration raw signals of measuring point A and other measuring points.

[0039] 3. Analysis of test data from the verification device After acquiring the raw vibration signals, they are analyzed using specialized vibration testing software, including... Vibration Time Domain and Spectrum Analysis: Through time domain analysis, if measuring point A only fluctuates with a large amplitude in the idle state, and has no fluctuation and a small amplitude in other states, it can be considered that the abnormal signal only exists in the idle state. In the idle state, the engine speed is approximately 1200 rpm, with a power frequency of approximately 20 Hz. The narrow bandwidth speed tracking method aims to collect the vibration amplitude at the engine's power frequency, i.e., 20 Hz ± 1 Hz. Further spectrum analysis of measuring point A reveals low-frequency signals (0~20) Hz, which can be considered as interference or cumulative errors caused by the quadratic integral trend term. These low-frequency signals can only be collected by the narrow bandwidth speed tracking method in the low-speed engine state, leading to fluctuating vibration values ​​measured at measuring point A in the idle state, even exceeding limits. After the above confirmation and analysis, the vibration fluctuations or exceeding limits are not caused by the engine itself, but by low-frequency signals.

[0040]

Example 2

[0041] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for verifying vibration of an entire machine, characterized in that, include: Install a vibration raw signal acquisition device to obtain the raw signal at measurement point A; The original signal at measurement point A was subjected to vibration time-domain and spectral analysis to obtain the analysis results. The analysis results were then used to verify whether vibration abnormalities had occurred.

2. The whole-machine vibration verification method according to claim 1, characterized in that, The original signal at measurement point A is subjected to vibration time-domain and spectral analysis to obtain analysis results. The analysis results are then used to verify whether vibration anomalies have occurred. Specifically, this includes: Vibration time-domain analysis is performed on the original signal of measuring point A. If measuring point A only jumps in the slow state and the amplitude is within the abnormal threshold range, and there is no jumping in other states and the amplitude is within the small amplitude threshold, then the analysis result is that there is an abnormal signal in the slow state, which causes the vibration amplitude to jump. Spectral analysis of the abnormal signal reveals that if a low-frequency signal of 0-20 Hz is present, the abnormality is caused by interference; otherwise, the abnormality is attributed to engine vibration.

3. The whole-machine vibration verification method according to claim 2, characterized in that, The abnormal threshold range is defined as the vibration amplitude randomly fluctuating between 10μm and 70μm, or exceeding the limit of 80μm.

4. The whole-machine vibration verification method according to claim 2, characterized in that, The small amplitude threshold is a vibration amplitude of no more than 20 μm.

5. The whole-machine vibration verification method according to claim 1, characterized in that, After installing the vibration original signal acquisition device, first verify that the static connection of the device is complete, then power it on for inspection. After confirming that there are no errors, start the engine test run to obtain the voltage signal at measurement point A.

6. The whole-machine vibration verification method according to claim 1, characterized in that, The vibration raw signal acquisition device includes: a dedicated adapter plug (1) for measuring point A, which is plugged into the engine socket. The dedicated adapter plug (1) for measuring point A is connected to a charge amplifier (3), which is connected to a data acquisition system (5), which is connected to a host computer.

7. The whole-machine vibration verification method according to claim 6, characterized in that, The A-point dedicated adapter plug (1) includes a housing with signal + and signal - on it, which are used to test and transmit charge signals after connection.

8. The whole-machine vibration verification method according to claim 6, characterized in that, The dedicated adapter plug (1) for measuring point A transmits the charge signal to the charge amplifier (3) in the test bench control room via the low-noise shielded cable (2) of the test bench.

9. The whole-machine vibration verification method according to claim 6, characterized in that, The charge amplifier (3) transmits the voltage signal to the data acquisition system (5) via a double-ended BNC line (4).

10. The whole-machine vibration verification method according to claim 6, characterized in that, The data acquisition system (5) transmits data to the host computer via a data transmission network cable (6).

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