轴颈倾斜对内燃机主轴承润滑和磨损的影响

An Influence of Journal Misalignment on Lubrication and Wear of Main Bearings of ICE

建立内燃机主轴承热弹性流体动力润滑模型,考虑轴颈倾斜,以粗糙接触压力表征轴颈与轴瓦的磨损程度。通过对不同工况下主轴颈倾斜角度、粗糙接触压力等的计算,研究轴颈倾斜对主轴承润滑和磨损的影响。结果表明,轴颈不对中倾斜角度较小时,主轴承仍能够处于流体润滑状态;轴颈倾斜角度较大时,轴承处于边界润滑状态,出现偏摩擦磨损。转速和负荷对轴颈倾斜影响较大,高转速和满负荷时轴承的润滑不良,磨损较大。

A model was established to simulate thermoelastohydrodynamic lubrication and wear ot mare bearings ot ICE considering journal misalignment. The extents of wear between journal and shell can be signified by asperity contact pressures. The influences of journal misalignment on the lubrication and wear were investigated based on the calculation of journal incline degrees and asperity contact pressures under different engine operation conditions. The results show that the main bearings can still be in a state of fluid lubrication when the journal misalignment angles are small. Otherwise, the bearings are in boundary lubrication, and in abnormal friction under the condition of large journal tilt angles. Speeds and loads have a greater imoact on the iournal misalignmant,especially under high-speeds and full loads.