The structural characteristics and cases of handling abnormal vibration faults of various axial flow fans were summarized.The reasons for particular vibration problems of the axial flow fan were analyzed in detail From the rotor blade adjustment structure aspect

the single stage impeller blade opening is not synchronous

the two stage impeller blade opening is not synchronous and the eccentricity of adjustment component itself are the major reasons for fan vibration.From the flow pulsation aspect

the flow turbulence and pulsation caused by flow rotating component fault mainly results in the fan vibrations.From the support dynamic stiffness and resonance aspect

the weak support dynamic stiffness of the fan itself

the weak support dynamic stiffness of the fan caused by loose connection and local resonance are main reasons for fan vibrations.Moreover

combining with the fan structure

this paper also mentions the possible fault locations on the wind turbine

and proposes the corresponding maintenance advices.