Structure safety design strategy of rotor-support system due to fan blade loss

Taking the high bypass ratio turbofan engines as the research object for the rotor-support system under the load of blade loss, the strategies of structural safety design were put forward for the supporting scheme with loading distribution, variable stiffness support structure and the deformation control of support structure. Combined with the dynamic design on rotor, the safety design was realized. Research showed that, the variable stiffness support design at the rear bearing could reduce the critical speed and corresponding vibration amplitude, leading to local vibration of the fan during the process of slowing down. Through the design on cone angle of the conical shell at the ball bearing, decreasing the influence of shaft deformation on the ball bearing and the support could withstand the big axial direction load. The design of drum-like matching interface between the bottom of bearing case and rotating shaft could avoid the support deformation through the matching surfaces slipping upon each other, thus ensuring the safety of the bearing. The research results can provide a technical reference for safety design on high bypass ratio turbofan engines under severe loadings.