摘要
针对柴油机标定工况和单缸停油工况,建立了工作过程的仿真模型,计算了缸内气体压力。基于Reynold方程、Greenwood/Tripp微凸体接触模型和多体动力学模型对主轴承的润滑状态进行分析。以某六缸柴油机为研究对象,以标定工况和50%功率、单缸停油工况为计算工况进行了试验。研究结果表明:第三缸停油最小油膜厚度比标定工况的大,其他缸停油最小油膜厚度均变小,最小值出现在第一缸停油第七主轴承。第一缸停油时,主轴承摩擦功率变小,功率的有效输出能力降低;第七主轴承下轴瓦靠近飞轮一侧的边缘发生微凸体接触。标定工况最小油膜厚度为2.07μm,第一缸停油最小油膜厚度为1.82μm,相差12.1%;标定工况最大油膜压力为52.5MPa,第一缸停油最大油膜压力为50.0MPa,相差4.8%。
A simulation model of diesel engine work process under rated condition and single cylinder fuel cutoff condition was established to calculate in-cylinder gas pressure. Based on Reynolds equation, Greenwood/Tripp asperities contact model and multi-body dynamics model, the lubrication state of main bearing was analyzed by taking a six-cylinder diesel engine as a study object, and rated condition, 50% power condition as well as single cylinder fuel cutoff condition as simulation conditions. Results show that the mini- mum oil film thicknesses of all main bearings decrease under each cylinder fuel cutoff condition except the third cylinder fuel cutoff when the minimum oil film thicknesses are greater than under the rated condition; the minimum value appears at the 7th main bearing under the 1st cylinder fuel cutoff condition. When the 1st cylinder fuel is cutoff, the friction power decreases, but the ability to output effective work is reduced; as- perities contact takes place at the edge of the 7th lower half main bearing near the flywheel. The minimum oil film thickness value is 2.07 μm under the rated condition and 1.82 μm under the 1st cylinder cutoff condition, with 12.1% in difference; the peak oil pressure is 52.5 MPa under the rated condition and 50.0 MPa under the 1st cylinder cutoff condition, with 4.8% in difference.
出处
《内燃机工程》
EI
CAS
CSCD
北大核心
2014年第6期25-30,共6页
Chinese Internal Combustion Engine Engineering
基金
国家"八六三"高技术研究发展计划项目(2012AA1117065)
关键词
内燃机
单缸停油
缸内工作过程
主轴承润滑
多体动力学
IC engine
single cylinder fuel cutoff
in-cylinder work process
main bearing lubrication
multi-body dynamics
