The inlet oil temperature of the rotor system with high-speed and light-load turbocharger will change during operation, which will change the vibration characteristics of the rotor system and even cause vibration accidents. Taking a certain type of high-speed and light-load turbocharger rotor system as the research object, the changes in oil film viscosity, friction power consumption, oil film temperature rise, and ring speed ratio with the inlet oil temperature of floating ring bearings are analyzed. A dynamic finite-element model of the turbocharger rotor–floating-ring-bearing system is constructed, and the finite-element model is verified through the critical speed and colormap spectrogram. The Newmark integral method is used to analyze the nonlinear transient response of the rotor system, and the influence of the inlet oil temperature on the vibration response characteristics of the rotor system is studied. The results show that an increase in the inlet oil temperature leads to a decrease in the internal and external oil film viscosities, frictional power consumption, temperature rise, and an increase in the ring speed ratio. When the inlet oil temperature increases from 50 °C to 130 °C, the amplitude of the inner oil film oscillation will gradually decrease, but the amplitude of the outer oil film vortex will gradually increase, and the journal speed point where the inner oil film oscillation and the outer oil film vortex will appear about 30% in advance. In summary, the rotor vibration is better when the inlet oil temperature is about 90 °C. The conclusion of this paper can provide a theoretical reference for selecting the operating parameters of the rotor system with the least vibration for high-speed light-load turbochargers.

带有高速和轻载涡轮增压器的转子系统的入口油温在运行过程中会发生变化，这将改变转子系统的振动特性，甚至引起振动事故。以某类高速轻载涡轮增压器转子系统为研究对象，油膜粘度，摩擦功率消耗，油膜温升以及与浮动环轴承进口油温的环速比的变化为分析。建立了涡轮增压器转子-浮动环-轴承系统的动态有限元模型，并通过临界转速和色图谱图验证了该有限元模型。Newmark积分法用于分析转子系统的非线性瞬态响应，研究了进油温度对转子系统振动响应特性的影响。结果表明，入口油温的升高导致内部和外部油膜粘度的降低，摩擦功率消耗，温度升高以及环速比的提高。当入口油温从50°C升高到130°C时，内部油膜振荡的振幅将逐渐减小，但是外部油膜涡旋的振幅将逐渐增加，并且内部油膜的轴颈速度点振荡和外油膜涡旋将提前出现约30％。总之，当进口机油温度约为90°C时，转子振动会更好。