Abstract：The characteristics of vehicular turbocharger, namely, ultra speed, light load, great flexibility, multi excitations and various working conditions, determine the frequent change of speed in a relatively wide range of the bearing-rotor system. A rotor model considering seal structure and gas-exciting force was established based on a certain mode of vehicular turbocharger. The transient responses of the bearing-rotor system in different values of acceleration and deceleration were achieved and compared with numerical and experimental calculations of critical speed and steady-state response of the vehicular turbocharger's ball bearing-rotor system. Results showed that the first order critical speed decreases and the second order critical speed increases with the raise of acceleration (deceleration) of ball bearing turbocharger. Amplitude of ball bearing vehicular turbocharger rotating near critical speeds increases as the acceleration (deceleration) raises , while amplitude varies little beyond the near range of critical speeds.
2014, Vol. 33 
