内燃机曲柄连杆机构冲击动力学分析

Dynamic Analysis of Shock Response for Crank and Connecting Rod Mechanism in Diesel Engines

基于多体动力学和有限元方法,以柴油机曲柄连杆机构为研究对象,综合考虑机构内部复杂的接触关系、主轴承油膜刚度、轴承间隙以及非线性因素,分别在柴油机额定工况和静止工况下,基于BV043/1985标准对机构进行抗冲击性能评估。结果表明:机构符合BV043/1985标准关于冲击安全级A级设备的相关要求,且在额定工况下的冲击响应高于静止工况;曲轴的冲击响应高于连杆。因此,需重点考虑:主轴承油膜刚度和轴承间隙对机构的冲击性能有较大影响,进行冲击动力学分析时不可忽略。

Based on multi-body system dynamics and FEM, considering complicated contact relationships, oil membrane stiffness of main bearings, bearing gap and some other non-linear factors, the shock response characteristics of the crank and connecting rod mechanism in a diesel engine was analyzed. Its shock-resistance performance was predicted and evaluated under rated condition and static condition respectively on the basis of BV043/1985 standard. The results indicate that the crank and connecting rod mechanism can meet BV043/1985 standard on impact security level of A-grade equipments, and the shock response stress of the mechanism under rated condition was greater than that under static condition, and the shock response stress of the crank was greater than that of the connecting rod. The oil membrane stiffness of main bearings and the bearing gap have a great influence on the shock response stress of the crank and connecting rod.