軸受け部の潤滑油温度分布を考慮したターボチャージャーの機械損失予測モデル

抄録

Recently, the downsizing turbo is widespreading to satisfy the emission regulations of automobiles. It is necessary to develop the model to predict the mechanical loss in a turbocharger in the model-based development. In our previous research, a mathematical model with the mechanical loss caused by the bearings used in a turbocharger was developed. In the previous model, the friction loss is estimated by lubricant temperature, lubricant flow, thrust force and rotation of the turbocharger. The lubricant temperature applied in the previous model was the average temperature of the inlet and the outlet. However, the inner lubricant temperature is higher than the outer lubricant temperature in the journal bearing, then it is inappropriate to apply the average temperature. This research aimed to improve the accuracy of the previous model adding the prediction model of the lubricant temperature distribution in the journal bearing. We estimated the lubricant temperature distribution in the journal bearing by calculating the Reynolds equation and energy equation iteratively. The result revealed that the lubricant temperature distribution in the axis direction, and the predicted value came closer to the measured value than the previous model in case the supply lubricant temperature is low.