A Cooling Fan Bearing Fault Diagnosis And State Evaluation

With the rapid development of information technology and microelectronicstechnology, the heat flux density of electronic devices continue to increase, powerconsumption is increasing, and electronic equipment develop toward lighter and thinnerdirection, the cooling of electronic equipment is becoming increasinglyprominent. The cooling fan as the key components of cooling system in electronicequipment plays a vital role to ensure stable and reliable operation of the system. Therolling bearing as the core component of cooling fans, most of the cooling fan failuremainly concentrated in the bearing fault. Therefore, to carry out fault diagnosis andcondition assessment of cooling fan bearing can effectively guarantee the reliability ofthe electronic equipment operation and prolong the service life of electronic equipment.In this paper, a series of fault diagnosis and state evaluation studies are carried outbased on cooling fan bearing vibration mechanism and operation mode. The maincontents include: analyze the structure of the cooling fan, and review the rolling bearingvibration mechanism and signal characteristics. Some signal processing technologiesincluding EMD decomposition, wavelet analysis, AR regression linear prediction andMED filtering etc. are used to analyze the cooling fan bearing vibration signal, andrealize the fault detection of cooling fan bearing. Meanwhile, a special comb toothshape filter is constructed to establish a health index from the frequency domain ofvibration signal, which is used to monitor the health status of cooling fan bearing. Inaddition, SVM technology is used to classify and identify the health states of coolingfan bearing in the paper, and then a degradation index is constructed based on the resultsto assess the degradation level of cooling fan bearing.