Abstract: In order to solve the vibration problem in the lube oil cooling fan, a bearing-rotor-structure with damping structure was established, and the damping seat on the rotor was analyzed. Firstly, according to the damping mechanism, the influence of different thickness of aluminum foam damping material on the static strength and modal damping ratio of bearing housing is analyzed, and the optimal damping layer thickness is determined. Secondly, the finite element model of bearing house-bear-rotor structure with damping structure is established. Finally, the damping effect of the rotor structure with or without damping layer is compared under the same excitation conditions. The results show that the vibration attenuation of the rotor is obviously accelerated, the amplitude is reduced, the damping effect is significant.