Aero-engine ball bearing outer ring peeling fault on-board early warning method

Abstract

The application belongs to the technical field of on-board early warning of ball bearing outer ring peeling faults in an aero-engine, and particularly relates to an on-board early warning method for ball bearing outer ring peeling faults in an aero-engine, which fuses feature quantities extracted based on a wavelet envelope spectrum and a specified frequency band filtering method through fuzzy processing, and constructs a feature quantity for fault warning again, compares the fused feature quantity with a fault threshold value to determine whether a ball bearing outer ring peeling fault occurs, and performs early warning. The overall calculation amount is not large, the calculation speed is relatively fast, and the demand for on-board early warning of ball bearing outer ring peeling faults in an aero-engine can be well met.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of on-board early warning of ball bearing outer ring peeling failure in an aero-engine, and particularly relates to an on-board early warning method for ball bearing outer ring peeling failure in an aero-engine. BACKGROUND

[0002] The main bearing of an aero-engine often fails, which endangers the safe use of the aero-engine. A large number of main bearing failure analysis results show that the main failure mode of the aero-engine is ball bearing outer ring peeling failure.

[0003] Currently, the vibration signal processing methods such as sparse decomposition and singular value decomposition or the spectrum analysis method are mainly used for early warning of ball bearing outer ring peeling failure in an aero-engine.

[0004] The vibration signal processing methods such as sparse decomposition and singular value decomposition involve complex matrix operations in the calculation process, have low calculation efficiency, and are easy to exceed the on-board system memory.

[0005] The spectrum analysis method directly searches for the characteristic frequency of ball bearing outer ring peeling failure from the spectrum. Due to the interference of the complex structure and transmission path inside the aero-engine, the ball bearing outer ring peeling failure feature is severely attenuated when transmitted to the engine case, the ball bearing outer ring peeling failure information in the vibration signal is extremely weak, and the signal-to-noise ratio is extremely low. Therefore, it is difficult to extract the ball bearing outer ring peeling failure characteristic frequency from the vibration signal. In addition, the ball bearing is an angular contact ball bearing, the contact angle has a certain range of variation, and there is a certain slip phenomenon, which causes the ball bearing outer ring peeling failure characteristic frequency to have a certain range of variation. In the case where the range of variation of the ball bearing outer ring peeling failure characteristic frequency is not clear, directly searching for the characteristic frequency of ball bearing outer ring peeling failure from the spectrum will result in a large error, thereby causing false negatives and false positives.

[0006] The present application is proposed in view of the above technical defects.

[0007] It should be noted that the disclosure of the above background art content is only used to assist in understanding the inventive concept and technical solutions of the present application, and it does not necessarily belong to the prior art of the present application. In the absence of clear evidence that the above content has been disclosed on the filing date of the present application, the above background art should not be used to evaluate the novelty and inventiveness of the present application. SUMMARY

[0008] The purpose of the present application is to provide an on-board early warning method for ball bearing outer ring peeling failure in an aero-engine to overcome or alleviate at least one aspect of the known technical defects.

[0009] The technical solution of the present application is:

[0010] An aero-engine ball bearing outer ring peeling fault on-board early warning method, comprising:

[0011] Ball bearing outer ring peeling fault frequency feature extraction step:

[0012] The vibration signal is decomposed by 5 layers using db8 wavelet base, and 5 detail signals and 1 approximation signal are obtained;

[0013] Each sub-signal is envelope demodulated;

[0014] Each sub-signal is normalized autocorrelation denoised;

[0015] Each sub-signal is spectrum analyzed to obtain a wavelet envelope spectrum reflecting the frequency feature of the health condition of the ball bearing outer ring;

[0016] The ball bearing contact angle change range is determined to obtain the ball bearing outer ring peeling fault characteristic frequency change range [f o1 ,f o2 ], and the maximum value of the spectrum line in the frequency range is searched from each wavelet envelope spectrum:

[0017] A l =max[W l (f o1 +i△f)],i∈[0,m],l=1,2,3,4,5,6;

[0018] m=δf / △f;

[0019] δf=f o2 -f o1 ;

[0020] Wherein,

[0021] A l is the maximum value of the spectrum line in the [f o1 ,f o2 ] frequency range in the lth wavelet envelope spectrum;

[0022] W l (f o1 +i△f) is the spectrum line value at f o1 +i△f frequency in the lth wavelet envelope spectrum, and △f is the frequency interval in the wavelet envelope spectrum;

[0023] δf is the tolerance range of the ball bearing outer ring peeling fault characteristic frequency;

[0024] The average value of each wavelet envelope spectrum is calculated:

[0025]

[0026] Wherein,

[0027] is the average value of the first wavelet envelope spectrum;

[0028] W l is the value of the first wavelet envelope spectrum of the jth spectral line; j ) is the value of the first wavelet envelope spectrum of the jth spectral line;

[0029] N e is the number of spectral lines of the wavelet envelope spectrum;

[0030] The maximum value of the spectral line of each wavelet envelope spectrum in the frequency range [f o1 ,f o2 ] is dimensionless:

[0031]

[0032] wherein,

[0033] F ol is the dimensionless value of the maximum value of the spectral line of the first wavelet envelope spectrum in the frequency range [f o1 ,f o2 ];

[0034] The maximum value of the dimensionless spectral line of each wavelet envelope spectrum in the frequency range [f o1 ,f o2 ] is selected as the ball bearing outer ring fault feature value F o :

[0035]

[0036] The ball bearing outer ring fault feature value F o is converted into a fault frequency feature F dB , which is output in dB value:

[0037] F dB = 20log(F o ).

[0038] Ball bearing outer ring peeling fault frequency band energy feature extraction step:

[0039] The vibration signal is filtered by setting the frequency to obtain a filtered signal;

[0040] The filtered signal is normalized and autocorrelated to reduce noise;

[0041] The effective value of the filtered signal is calculated as the ball bearing outer ring peeling fault frequency band energy feature FBE5.

[0042] Ball bearing outer ring peeling fault feature fusion step:

[0043] The ball bearing outer ring fault frequency feature FdB The fuzzification processing is performed:

[0044]

[0045] wherein,

[0046] μ F3 (F dB ) is a fuzzification processing value of the ball bearing outer ring fault frequency characteristic quantity;

[0047] Th 01 is an alarm limit of the ball bearing outer ring fault frequency characteristic quantity;

[0048] Th 02 is an abnormal limit of the ball bearing outer ring fault frequency characteristic quantity;

[0049] The ball bearing outer ring spalling fault frequency band energy characteristic quantity FBE5 is subjected to fuzzification processing:

[0050]

[0051] wherein,

[0052] μ F3 (FBE5) is a fuzzification processing value of the ball bearing outer ring fault frequency band energy characteristic quantity;

[0053] Th 11 is an alarm limit of the ball bearing outer ring fault frequency band energy characteristic quantity;

[0054] Th 12 is an abnormal limit of the ball bearing outer ring fault frequency band energy characteristic quantity;

[0055] The ball bearing outer ring spalling fault characteristic fusion characteristic quantity F V3 is calculated:

[0056]

[0057] wherein,

[0058] R 31 is a fuzzy relationship between the frequency characteristic quantity and the ball bearing outer ring spalling fault;

[0059] R 32 is a fuzzy relationship between the energy characteristic quantity and the ball bearing outer ring spalling fault.

[0060] The ball bearing outer ring spalling fault judgment step:

[0061] The ball bearing outer ring spalling fault characteristic fusion characteristic quantity F V3 is compared with the fusion characteristic quantity fault threshold Th to judge whether the ball bearing outer ring spalling fault occurs;

[0062] If F V3 > Th, it is judged that the outer ring of the ball bearing is peeled off;

[0063] If F V3 ≤ Th, it is judged that the outer ring of the ball bearing is normal.

[0064] According to at least one embodiment of the present application, in the ball bearing outer ring peeling fault airborne early warning method of the aero-engine, in the ball bearing outer ring peeling fault frequency feature extraction step, the contact angle change range of the ball bearing is determined, specifically:

[0065] Taking the aero-engine 95% working condition above, the contact angle change range of the ball bearing is 20°-45°.

[0066] According to at least one embodiment of the present application, in the ball bearing outer ring peeling fault airborne early warning method of the aero-engine, in the ball bearing outer ring peeling fault frequency band energy feature extraction step, the vibration signal is filtered by setting frequency to obtain a filtered signal, specifically:

[0067] The vibration signal is filtered by 3125-6250Hz to obtain a filtered signal.

[0068] According to at least one embodiment of the present application, in the ball bearing outer ring peeling fault airborne early warning method of the aero-engine, in the ball bearing outer ring peeling fault feature fusion step, the ball bearing outer ring fault frequency feature quantity alarm limit Th 01 is taken as 15;

[0069] The ball bearing outer ring fault frequency feature quantity abnormal limit Th 02 is taken as 20;

[0070] The ball bearing outer ring fault frequency band energy feature quantity alarm limit Th 11 is taken as 0.05;

[0071] The ball bearing outer ring fault frequency band energy feature quantity abnormal limit Th 12 is taken as 0.1.

[0072] According to at least one embodiment of the present application, in the ball bearing outer ring peeling fault airborne early warning method of the aero-engine, in the ball bearing outer ring peeling fault judgment step, the ball bearing outer ring peeling fault fusion feature quantity fault threshold Th is taken as 0.5. BRIEF DESCRIPTION OF DRAWINGS

[0073] Fig. 1 is a schematic diagram of the ball bearing outer ring peeling fault airborne early warning method of the aero-engine provided by the embodiments of the present application;

[0074] Fig. 2The application provides an on-board early warning method for a ball bearing outer ring peeling fault in an aero-engine. The ball bearing outer ring peeling fault diagnosis is performed on two aero-engines with ball bearing outer ring peeling faults and two normal aero-engines. A comparison diagram of diagnosis results is shown. DETAILED DESCRIPTION

[0075] In order to make the technical solutions and advantages of the present application clearer, the technical solutions of the present application will be further described in detail below in combination with the drawings. It should be understood that the specific embodiments described herein are only part of the embodiments of the present application, and are only used to explain the present application, but not to limit the present application. It should be noted that, for the purpose of description, only parts related to the present application are shown in the drawings, and other related parts can be referred to the general design. In the case of no conflict, the embodiments in the present application and the technical features in the embodiments can be combined to obtain new embodiments.

[0076] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of the present application should be the general meanings understood by the general technical personnel in the field of the present application. The words indicating the relative direction or position relationship, such as "upper", "lower", "left", "right", "center", "vertical", "horizontal", "inner", "outer" and the like used in the description of the present application, are only used to indicate the relative direction or position relationship, and not to imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and the relative position relationship may also change accordingly when the absolute position of the described object changes, therefore it cannot be understood as a limitation on the present application. The "first", "second", "third" and the like used in the description of the present application are only for the purpose of description, and are used to distinguish different components, and cannot be understood as indicating or implying relative importance. The "one", "an" or "the" and the like used in the description of the present application should not be understood as an absolute limitation on the quantity, but should be understood as the presence of at least one. The "including" or "containing" and the like used in the description of the present application means that the elements or objects appearing before the word are covered by the elements or objects listed after the word and their equivalents, and other elements or objects are not excluded.

[0077] The drawings will be described below in combination with the Figs. 1-2 The present application will be further described in detail.

[0078] An on-board early warning method for a ball bearing outer ring peeling fault in an aero-engine, as shown in Fig. 1 The method comprises the following steps.

[0079] I. Ball bearing outer ring peeling fault frequency feature extraction step.

[0080] The vibration signal was decomposed into 5 levels using a db8 ​​wavelet basis, resulting in 5 detail sub-signals and 1 approximate sub-signal.

[0081] Envelope demodulation is performed on each sub-signal;

[0082] Normalized autocorrelation denoising is performed on each sub-signal;

[0083] Spectral analysis of each sub-signal yields the wavelet envelope spectrum, which reflects the frequency characteristics of the outer race health of the ball bearing.

[0084] Taking over 95% of the operating conditions of an aero-engine as an example, the contact angle of the ball bearing varies from 20° to 45°. Then, using the characteristic frequency calculation formula, the characteristic frequency variation range of the outer ring spalling fault in the ball bearing is calculated [f]. o1 ,f o2 Within this frequency range, search for the maximum spectral value from each wavelet envelope spectrum:

[0085] A l =max[W l (f o1 +i△f)], i∈[0,m], l=1, 2, 3, 4, 5, 6;

[0086] m = δf / △f;

[0087] δf=f o2 -f o1 ;

[0088] in,

[0089] A l For the l-th wavelet envelope spectrum in [f o1 ,f o2 The maximum value of the spectral line within the frequency range;

[0090] W l (f o1 +i△f) is the wavelet envelope spectrum of the l-th wavelet, in f o1 The spectral value at frequency +i△f, where △f is the frequency interval in the wavelet envelope spectrum;

[0091] δf represents the tolerance range of the characteristic frequency of outer ring spalling failure in ball bearings;

[0092] Take 10Hz~f o1 +f o2 The number of spectral lines in the wavelet envelope spectrum within the frequency range is N. e Calculate the average value of each wavelet envelope spectrum:

[0093]

[0094] in,

[0095] is the average value of the first wavelet envelope spectrum;

[0096] W l is the value of the first wavelet envelope spectrum at the jth spectral line; j

[0097] The maximum value of the spectral line of each wavelet envelope spectrum in the frequency range [f o1 , f o2 ] is dimensionless:

[0098]

[0099] wherein,

[0100] F ol is the dimensionless value of the maximum value of the spectral line of the first wavelet envelope spectrum in the frequency range [f o1 , f o2 ];

[0101] The maximum value of the dimensionless spectral line of each wavelet envelope spectrum in the frequency range [f o1 , f o2 ] is selected as the ball bearing outer ring fault feature value F o :

[0102]

[0103] The ball bearing outer ring fault feature value F o is converted into a fault frequency feature F dB , which is output in dB value:

[0104] F dB = 20log(F o ).

[0105] II. Ball bearing outer ring peeling fault frequency band energy feature extraction steps.

[0106] The vibration signal is filtered by 3125-6250Hz to obtain a filtered signal;

[0107] The filtered signal is normalized and autocorrelated to reduce noise;

[0108] The effective value of the filtered signal is calculated as the ball bearing outer ring peeling fault frequency band energy feature FBE5.

[0109] III. Ball bearing outer ring peeling fault feature fusion steps.

[0110] The ball bearing outer ring fault frequency feature F dB is fuzzified:

[0111] ​

[0112] wherein,

[0113] μ F3 (F dB ) is the fuzzy processing value of the ball bearing outer ring fault frequency characteristic quantity;

[0114] Th 01 is the alarm limit of the ball bearing outer ring fault frequency characteristic quantity, which can be taken as 15;

[0115] Th 02 is the abnormal limit of the ball bearing outer ring fault frequency characteristic quantity, which can be taken as 20;

[0116] The ball bearing outer ring spalling fault frequency band energy characteristic quantity FBE5 is subjected to fuzzy processing:

[0117]

[0118] wherein,

[0119] μ F3 (FBE5) is the fuzzy processing value of the ball bearing outer ring fault frequency band energy characteristic quantity;

[0120] Th 11 is the alarm limit of the ball bearing outer ring fault frequency band energy characteristic quantity, which can be taken as 0.05;

[0121] Th 12 is the abnormal limit of the ball bearing outer ring fault frequency band energy characteristic quantity, which can be taken as 0.1;

[0122] The ball bearing outer ring spalling fault characteristic fusion characteristic quantity F V3 is calculated:

[0123]

[0124] wherein,

[0125] R 31 is the fuzzy relationship between the frequency characteristic quantity and the ball bearing outer ring spalling fault, which is 1.0 by default;

[0126] R 32 is the fuzzy relationship between the energy characteristic quantity and the ball bearing outer ring spalling fault, which is 1.0 by default.

[0127] Four, the ball bearing outer ring spalling fault judgment steps.

[0128] The ball bearing outer ring spalling fault characteristic fusion characteristic quantity F V3 is compared with the fusion characteristic quantity fault threshold Th to determine whether the ball bearing outer ring spalling fault occurs.

[0129] If F V3 > Th, it is judged that the ball bearing outer ring peeling failure occurs;

[0130] If F V3 ≤ Th, it is judged that the ball bearing outer ring is normal.

[0131] Th can be 0.5.

[0132] The early warning duration of the ball bearing outer ring peeling failure is the interval between the time when the ball bearing outer ring peeling failure is judged to occur and the time when the ball bearing fails.

[0133] In one specific embodiment, the above-mentioned ball bearing outer ring peeling failure on-board early warning method in an aero-engine is used to diagnose the ball bearing outer ring peeling failure of two aero-engines with ball bearing outer ring peeling failure and two normal aero-engines, and the diagnosis results are as shown in Table 1. Fig. 2 As can be seen from Table 1, the feature fusion feature F V3 of the aero-engine with ball bearing outer ring peeling failure is significantly greater than 0.5, and has a clear failure evolution trend, and the feature fusion feature F V3 of the normal aero-engine is significantly less than 0.5. The comprehensive diagnosis rate of the aero-engine with ball bearing outer ring peeling failure is 92.14%, and the comprehensive diagnosis rate of the normal aero-engine is 99.82%, which is significantly higher than the diagnosis results of only using the ball bearing outer ring peeling failure frequency feature and the ball bearing outer ring peeling failure frequency band energy feature.

[0134] The above-mentioned ball bearing outer ring peeling failure on-board early warning method in an aero-engine discloses that the feature quantities extracted based on the wavelet envelope spectrum and the specified frequency band filtering are fused through fuzzy processing, and a feature quantity for failure warning is constructed twice. Whether the ball bearing outer ring peeling failure occurs is judged by comparing the fusion feature quantity with the failure threshold, and early warning is performed. The overall calculation amount is not large, the calculation speed is fast, and the demand for on-board early warning of the ball bearing outer ring peeling failure in an aero-engine can be well met.

[0135] The aero-engine ball bearing outer ring peeling fault on-board early warning method disclosed in the above embodiment, on the one hand, starts from the ball bearing fault characteristic frequency, adaptively extracts the resonance frequency band of the vibration signal, performs envelope analysis and autocorrelation noise reduction, extracts the ball bearing outer ring peeling fault characteristic frequency from the envelope signals of different frequency bands, can highlight the periodic impact characteristics of the ball bearing outer ring peeling fault to the greatest extent, filter out noise and other clutter interference, at the same time, considering the influence of the contact angle change of the ball bearing, selecting the contact angle range ensures the correctness and effectiveness of the extraction of the ball bearing fault characteristic frequency, through envelope analysis and autocorrelation noise reduction processing in different frequency bands, directly extracting the normalized ball bearing outer ring peeling fault frequency characteristic quantity from the envelope spectrum can effectively avoid false negatives and false positives caused by changes in the ball bearing outer ring peeling fault characteristic frequency, thereby improving the accuracy of the ball bearing outer ring peeling fault early warning.

[0136] The aero-engine ball bearing outer ring peeling fault on-board early warning method disclosed in the above embodiment, on the one hand, starts from the ball bearing fault characteristic frequency, adaptively extracts the resonance frequency band of the vibration signal, performs envelope analysis and autocorrelation noise reduction, extracts the ball bearing outer ring peeling fault characteristic frequency from the envelope signals of different frequency bands, can highlight the periodic impact characteristics of the ball bearing outer ring peeling fault to the greatest extent, filter out noise and other clutter interference, at the same time, considering the influence of the contact angle change of the ball bearing, selecting the contact angle range ensures the correctness and effectiveness of the extraction of the ball bearing fault characteristic frequency, through envelope analysis and autocorrelation noise reduction processing in different frequency bands, directly extracting the normalized ball bearing outer ring peeling fault frequency characteristic quantity from the envelope spectrum can effectively avoid false negatives and false positives caused by changes in the ball bearing outer ring peeling fault characteristic frequency, thereby improving the accuracy of the ball bearing outer ring peeling fault early warning.

[0137] The designated frequency band filtering can avoid interference from other frequency bands, avoid false positives, and filter out noise and other clutter interference using the autocorrelation noise reduction method, which can effectively extract the periodic impact signal characteristics caused by the ball bearing outer ring peeling fault, and can more accurately reflect the fault state of the ball bearing outer ring peeling.

[0138] The aero-engine ball bearing outer ring peeling fault on-board early warning method disclosed in the above embodiment combines the fault frequency characteristic quantity and the frequency band energy characteristic quantity, which can further improve the reliability and accuracy of the ball bearing outer ring peeling fault early warning.

[0139] The embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts of each embodiment can be referred to each other.

[0140] So far, the technical scheme of the present application has been described in combination with the preferred embodiments shown in the drawings. Those skilled in the art should understand that the protection scope of the present application is obviously not limited to these specific embodiments. Without deviating from the principles of the present application, those skilled in the art can make equivalent changes or replacements to related technical features, and the technical schemes after these changes or replacements will fall within the protection scope of the present application.

Claims

1. An on-board early warning method for ball bearing outer race spalling failure in an aero-engine, characterized in that, The method comprises the following steps: The frequency feature extraction step of the peeling failure of the outer ring of the ball bearing comprises the following steps: The vibration signal is decomposed by using a db8 wavelet base to obtain 5 detail signals and 1 approximation signal; The envelope demodulation is performed on each sub-signal; The normalized autocorrelation noise reduction is performed on each sub-signal; The frequency spectrum analysis is performed on each sub-signal to obtain a wavelet envelope spectrum, which reflects the frequency feature of the health status of the outer ring of the ball bearing; The variation range of the contact angle of the ball bearing is determined, and a variation range [f o1 ,f o2 ] of the peeling fault characteristic frequency of the outer ring of the ball bearing is obtained. In the frequency range, the maximum value of the spectral line is searched from each wavelet envelope spectrum. A l = max [W l (f o1 +i△f)], i ∈ [0,m], l = 1,2,3,4,5,6; M = δf / △f; δf = f o2 - f o1 ; Wherein, A l is the maximum value of the spectrum in the [f o1 ,f o2 ] frequency range in the first wavelet envelope spectrum. W l (f o1 +i△f) is the spectral line value in the lth wavelet envelope spectrum at f o1 +i△f frequency, and △f is the frequency interval in the wavelet envelope spectrum; δf is the tolerance range of the peeling failure feature frequency of the outer ring of the ball bearing; The average value of each wavelet envelope spectrum is calculated: Wherein, is the average value of the first wavelet envelope spectrum; W l (f j ) is the value of the jth spectral line of the first wavelet envelope spectrum; N e is the number of spectral lines of the wavelet envelope spectrum; The line maxima of each wavelet envelope spectrum are non-dimensionalized over the [f o1 ,f o2 ] frequency range: Wherein, F ol is the non-dimensional value of the spectral line maximum in the frequency range [f o1 ,f o2 ] for the first wavelet envelope spectrum; The maximum value of the dimensionless spectrum line in the [f o1 ,f o2 ] frequency range is selected as the ball bearing outer ring fault characteristic value F o : The ball bearing outer ring fault feature value F o The fault frequency feature quantity is converted to F dB Output in dB value: F dB = 20 log(F o ); The frequency band energy feature extraction step of the peeling failure of the outer ring of the ball bearing comprises the following steps: The vibration signal is filtered by using a set frequency to obtain a filtered signal; The normalized autocorrelation noise reduction is performed on the filtered signal; The effective value of the filtered signal is calculated as the peeling failure frequency band energy feature FBE5 of the outer ring of the ball bearing; The peeling failure feature fusion step of the outer ring of the ball bearing comprises the following steps: Ball bearing outer ring fault frequency characteristic quantity F dB Perform fuzzification processing: Wherein, μ F3 (F dB ) is the ball bearing outer ring fault frequency characteristic value after fuzzy processing; Th 01 is a fault frequency characteristic quantity alarm limit for the outer ring of the ball bearing; Th 02 is a ball bearing outer ring fault frequency characteristic quantity abnormal limit; The peeling failure frequency band energy feature FBE5 of the outer ring of the ball bearing is subjected to fuzzy processing: Wherein, μ F3 (FBE5) is the ball bearing outer ring fault band energy feature value after fuzzy processing; Th 11 is a fault band energy feature quantity alarm limit for the outer ring of the ball bearing. Th 12 is a fault band energy feature quantity abnormal limit for the outer ring of the ball bearing; Computing a feature fusion quantity F of a peeling failure characteristic of a ball bearing outer ring V3 : Wherein, R 31 The frequency feature quantity is a fuzzy relationship between the frequency feature quantity and the peeling failure of the outer ring of the ball bearing. R 32 The energy feature quantity and the fuzzy relationship between the outer ring peeling fault of the ball bearing; The peeling failure judgment step of the outer ring of the ball bearing comprises the following steps: Fusion feature quantity F of comparative ball bearing outer ring peeling failure characteristic V3 , fusion feature quantity failure threshold Th, judge whether the ball bearing outer ring peeling failure occurs; If F V3 > Th, it is judged that the outer ring of the ball bearing is peeled off. If F V3 ≤ Th, it is determined that the outer ring of the ball bearing is normal.

2. The method for early warning of the peeling failure of the outer ring of the ball bearing in the aero-engine according to claim 1, wherein In the frequency feature extraction step of the peeling failure of the outer ring of the ball bearing, the contact angle change range of the ball bearing is determined, and specifically: The contact angle change range of the ball bearing is 20°-45° under 95% working conditions of the aero-engine.

3. The method for early warning of the peeling failure of the outer ring of the ball bearing in the aero-engine according to claim 1, wherein In the frequency band energy feature extraction step of the peeling failure of the outer ring of the ball bearing, the vibration signal is filtered by using a set frequency to obtain a filtered signal, and specifically: The vibration signal is filtered by using 3125-6250 Hz to obtain a filtered signal.

4. The method for early warning of the peeling failure of the outer ring of the ball bearing in the aero-engine according to claim 1, wherein In the ball bearing outer ring peeling failure feature fusion step, the ball bearing outer ring failure frequency feature quantity alarm limit Th 01 Take 15; Ball bearing outer ring failure frequency characteristic quantity abnormal limit Th 02 Take 20; Ball bearing outer ring fault band energy characteristic quantity alarm limit Th 11 Take 0.05; Ball bearing outer ring failure band energy characteristic quantity abnormal limit Th 12 Take 0.

1.

5. The method for early warning of the peeling failure of the outer ring of the ball bearing in the aero-engine according to claim 1, wherein In the peeling failure judgment step of the outer ring of the ball bearing, the peeling failure fusion feature quantity fault threshold Th of the outer ring of the ball bearing is 0.5.

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