CN-121720716-B - Method and system for identifying vortex fault of main shaft inner ring of aero-engine

CN121720716BCN 121720716 BCN121720716 BCN 121720716BCN-121720716-B

Abstract

The invention relates to the technical field of main shaft detection of aeroengines, in particular to a method and a system for identifying vortex faults of an inner ring of a main shaft of an aeroengine. According to the method, vibration acceleration signals and rotation speed signals are synchronously collected, an order spectrum is generated by an order analysis method, 0.41-order energy is extracted from the order spectrum to serve as a characteristic, and the inner ring whirl fault is diagnosed by combining order stability and exclusive fault verification. The method accurately identifies vortex faults by judging whether 0.41-order energy exceeds a preset threshold value, whether the order is stable, removing common faults such as pitting/spalling and the like. In addition, by verifying the clearance fit, the light load working condition and the precondition of no sliding bearing, the reliability of fault diagnosis is ensured. Compared with the traditional fault diagnosis method, the method can effectively improve the early recognition capability of the vortex fault, avoid false alarm and missing alarm, and has stronger engineering application value.

Inventors

CHEN GUANGJIONG
ZENG YOUJIE
Pu Changman
LIAO WEIQING
LU YAO
HOU SEN
Qi Shaohuan
ZHANG MENGHUI

Assignees

杭州华翊科技有限公司

Dates

Publication Date: 20260508
Application Date: 20260210

Claims (10)

1. The method for identifying the whirl fault of the main shaft inner ring of the aero-engine is characterized by comprising the following steps: S1, synchronously collecting vibration acceleration signals at a target rolling bearing With spindle speed signal Wherein, the spindle rotation frequency is defined as the ratio of the spindle rotation speed to 60, and the ratio of any frequency to the spindle rotation frequency is defined as the order; S2, for the vibration acceleration signal Based on spindle rotation speed signal Is used for the analysis of the order of (a), generating an order spectrum Wherein For the purpose of the order of the steps, , In order for the frequency of the vibration to be the same, For the corresponding time point The lower order spectrum of the spectrum is obtained, The spindle rotates the frequency; S3, in-order spectrum Extracting the intensity index of the target order component, wherein the center order of the target order component is The intensity index is the order Energy of order The calculation formula is as follows: ; Wherein, the For the order of half-bandwidth, Is the magnitude of the order spectrum; S4, extracting the energy ratio of the BPFI/BPFO area, and calculating the orders corresponding to the frequencies of the BPFI and BPFO 、 And calculate the energy of the region And Respectively defined as: ; ; Wherein, the Is the pass-band width; S5, when Exceeds a preset threshold and the order stability index And when the preset stable condition is met and the exclusive fault checking result does not trigger the pitting/spalling fault, outputting the early warning of the inner ring whirling fault.
2. The method according to claim 1, wherein the step S3 further comprises: ; Wherein, the Is the half-band width of the order, Is the amplitude of the order spectrum, and Which is manifested as a sustained increase in energy over a plurality of successive time windows.
3. The method of claim 1, wherein the frequencies of BPFI and BPFO in step S4 are calculated as: ; ; Wherein, the For the number of rolling bodies, For the diameter of the rolling bodies, In order to achieve the pitch diameter, As a contact angle of the glass, Is the spindle rotation frequency.
4. The method according to claim 1, wherein the order stability index is in step S5 By calculating peak orders over a plurality of time windows The standard deviation is realized, and a specific calculation formula is as follows: Wherein, the For extraction within a time window The order value corresponding to the order is a value of the order, Is the standard deviation.
5. The method of claim 1, wherein step S4 further comprises calculating an energy ratio of the BPFI and BPFO regions And (3) with The definition is: ; Wherein, the For the total energy in the entire spectral interval, And (3) with Is the energy in the BPFI and BPFO region.
6. The method according to claim 1, wherein the precondition check in step S5 comprises: 1) Verifying whether the clearance between the shaft and the inner ring meets the geometric condition generated by vortex fault, and setting the clearance threshold value as When (when) When the vortex condition is judged to be met, c is an equivalent gap; 2) Checking whether the working condition is a light load condition, and setting a load factor Threshold of (2) When (when) When the load is a light load condition, judging; 3) Verifying whether the system contains a sliding bearing, and if the sliding bearing exists, not judging the inner ring whirl; And/or, the step S5 output includes: 1) When the early warning information of 'inner ring whirl' is output, additional maintenance suggestions are also included; 2) The maintenance advice at least comprises checking whether the surface of the shaft has abrasion marks, checking fit clearance, and adjusting the position of the oil supply system or the viscosity of oil.
7. An aircraft engine main shaft inner race whirl fault identification system for implementing the method of any one of claims 1-6, comprising: The device comprises a data acquisition module, an order analysis module and a characteristic extraction module, wherein the data acquisition module is used for synchronously acquiring a vibration acceleration signal and a main shaft rotating speed signal, the order analysis module is used for carrying out order analysis on the vibration acceleration signal according to the main shaft rotating speed signal and generating an order spectrum, and the characteristic extraction module is used for extracting 0.41-order energy And calculate the order stability index The device comprises a BPFI and BPFO area, an exclusive fault checking module, a precondition checking module and a judging and outputting module, wherein the BPFI and BPFO area energy ratio is calculated, the pitting/peeling fault is eliminated, the precondition checking module is used for checking whether the gap between a shaft and an inner ring, the working condition load and the structural configuration meet the precondition of the whirling fault, and the judging and outputting module is used for outputting the early warning information of the whirling fault of the inner ring according to multi-condition judging logic.
8. The system of claim 7, wherein the feature extraction module is further configured to calculate each time window based on the order spectrum Energy of order Judging whether to trigger vortex fault early warning based on a set threshold value; And/or the exclusive fault checking module calculates the energy ratio of the BPFI to the BPFO area And (3) with Comparing the detected value with a preset threshold value to remove pitting/peeling faults; And/or the judging and outputting module further provides maintenance suggestions for shaft surface inspection, fit clearance verification and oil supply system adjustment according to the output early warning information of the inner ring whirl fault.
9. A computer readable storage medium having stored thereon a computer program or instructions, which when executed by a processor, realizes the steps of the method of any of claims 1-6.
10. A computer program product comprising a computer program or instructions which, when executed by a processor, carries out the steps of the method of any one of claims 1 to 6.

Description

Method and system for identifying vortex fault of main shaft inner ring of aero-engine Technical Field The invention relates to the technical field of main shaft detection of aeroengines, in particular to a method and a system for identifying vortex faults of an inner ring of a main shaft of an aeroengine. Background Aero-engine main-shaft systems typically operate in high rotational speeds, high temperatures, complex loads and high vibration environments, with main-shaft rolling bearings as critical components for support and positioning, and with operational reliability directly related to engine safety and life. In order to ensure the load transmission and anti-inching capability of the rolling bearing, the engineering generally requires that the inner ring of the bearing and the main shaft are in interference fit or transition fit so as to inhibit the sliding and creeping of the inner ring relative to the main shaft, thereby reducing the inching wear of the matching surface, heat accumulation and the impact risk of the retainer. However, in some small aircraft engines or constructions where there is a high demand for ease of assembly and disassembly, the bearing inner race and the shaft may be in a clearance fit (e.g., similar to the H7/H6 rating) or may form an equivalent gap due to fretting wear after extended service. Under the conditions of high speed, light load and easy penetration of lubricating oil into the fit clearance, the clearance fit rolling bearing can form a local hydrodynamic oil film in the clearance between the shaft and the inner ring, so that the inner ring can perform asynchronous self-excitation movement relative to the shaft, and further, abnormal vibration modes different from the traditional pitting/peeling modes are induced. Because such failures often do not appear as significant raceway impact pulses, early diagnosis is difficult, but the consequences may continue to accumulate and eventually lead to wear of the spindle surface, abnormal impact of the bearing cage, and even shaft rejection, there is a need to comb existing diagnostic ideas and defects in the background art. In the existing rolling bearing fault diagnosis technical system, the most widely applied is a frequency spectrum criterion and a feature extraction method which are established around the contact defect (such as pitting, peeling, cracking and the like) of a rolling body-raceway. The typical practice is to calculate the fault characteristic frequency according to the bearing geometry and the rotation speed, such as inner ring passing frequency (BPFI), outer ring passing frequency (BPFO), harmonic waves, sidebands and the like, and find the corresponding peak value in the frequency domain, envelope spectrum or order spectrum of the vibration signal, so as to judge the fault type and severity. Meanwhile, aiming at the working condition of variable rotating speed, the industry generally adopts an order tracking, time-frequency analysis and energy spectrum method to map vibration response to an order domain taking main shaft rotating frequency as a reference, so that the resolution of fault components under the condition of rotating speed fluctuation is improved. For example, chinese patent CN106769033B discloses a recognition framework for variable-speed rolling bearings, which generally implements synchronous resampling or order analysis through a rotation speed signal, and extracts fault energy and ridge line characteristics in order domain/time-frequency domain for typical rolling bearing fault recognition and classification. The technology is effective for periodic impact/modulation caused by the partial damage of the roller path, but the focus is still on impact defect mechanisms such as BPFI/BPFO and the like, and a special mechanism constraint and discrimination structure is lacking for non-contact type matching failure (such as self-excitation whirling of an inner ring relative to a shaft) caused by a fit clearance, so that missing detection or misjudgment is easy to occur. In addition to conventional race damage diagnostics, some of the prior art attempts have also been made to monitor the running/loose fit/inner race relative rotation. Chinese patent CN112393907B discloses an automatic diagnosis scheme based on sweep frequency analysis/spectrum comparison, which can extract a target frequency point from a vibration response of a device and compare the target frequency point with a preset fault frequency point set, so as to identify and alarm a bearing fault or a race phenomenon. The scheme has the advantages of better automation and engineering suitability, but the nature of the scheme is still biased to a frequency point matching-experience rule path, namely, fault frequency points or characteristic intervals are usually required to be set a priori, and the scheme takes the defects or generalized anomalies of rolling bodies as objects, and does not establish a special judging chain for the specifi