Method for evaluating degradation of state of fan bearing

Abstract

The invention relates to a method for evaluating degradation of a state of a fan bearing. The method is especially suitable for fault diagnosis of a radiating fan bearing. The method comprises the following steps of: 1) acquiring an initial vibration signal; 2) performing zero-mean treatment on the initial vibration signal obtained in the step 1, thereby obtaining a pretreated vibration signal; 3) constructing a comb filter according to a fault characteristic frequency of a bearing element; 4) utilizing the comb filter to filter the pretreated vibration signal obtained in the step 2, thereby obtaining a filtered vibration signal; 5) performing Hilbert demodulation on the filtered vibration signal s2(t) obtained in the step 4, thereby obtaining an enveloped signal s3(t), and then performing Fourier transform, thereby obtaining an enveloped frequency spectrum S3(f); 6) utilizing the enveloped frequency spectrum S3(f) obtained in the step 5 to construct a health condition index (HCI) and an alarm threshold value (Th); and 7) realizing the fault diagnosis and state evaluation for the radiating fan bearing. The method has the beneficial effects that the fault state of a bearing can be efficiently monitored and an alarm can be given out.

Description

technical field [0001] The invention relates to the technical field of fault monitoring of mechanical and electronic products, in particular to fault diagnosis and state degradation evaluation of cooling fan bearings of electronic and electrical equipment. Background technique [0002] With the development of microelectronics technology, the heat flux density of electronic devices is increasing, the integration of electronic equipment is getting higher and higher, and the power consumption is increasing; on the other hand, the design of electronic equipment tends to be light, thin and short, which makes the system The heat dissipation contradiction is becoming more and more prominent. Poor heat dissipation will cause the internal temperature of electronic equipment to rise, the system will run unstable, and even lead to failure of electronic components, which will eventually lead to serious consequences. As an effective forced cooling method, cooling fan is widely used in t...

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Problems solved by technology

[0004] The traditional bearing fault diagnosis method for key components of various large-scale equipment is mainly devoted to the fault identification and classification of components, and basically uses residual root mean square error (RMSE, Root Mean Square Error) and kurtosis ( Kurtosis) coefficient Ku and other time-domain statistical methods, so it cannot reflect the fault development trend and the health status of the equipment

In addition, the RMSE value reflects the energy of the overall vibration, which can be used as an evaluation index of the equipment health status, but it is not sensitive to the early failure of the bearing; the kurtosis coefficient reflects the impact of the vibration and is sensitive to the early failure, but with As the bearing fault develops, its value will gradually decrease

At the same time, the time-domain vibration signal is often polluted by a large amount of background noise, and the use of time-domain statistical indicators to evaluate the fault development trend and working condition of the bearing can easily lead to misjudgment

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