考虑摩擦效应的船用配气凸轮轴系动力学特性研究  

Tribo-dynamics characteristics on the valve camshaft in marine diesel

作　　者：华德良 史修江 施方鹏 卢熙群[1] HUA Deliang;SHI Xiujiang;SHI Fangpeng;LU Xiqun(College of Power and Energy Engineering,Harbin Engineering University,Harbin 150001,China)

机构地区：[1]哈尔滨工程大学动力与能源工程学院,黑龙江哈尔滨150001

出　　处：《振动工程学报》2025年第3期449-460,共12页Journal of Vibration Engineering

摘　　要：配气凸轮轴系是用于保证船用柴油机气门准时启闭的核心传动机构,因其凸轮轴系接触润滑状态恶劣、摩擦激励过大,易导致界面综合扭矩过大,从而出现凸轮轴系配气不均及接触疲劳等故障。考虑系统瞬变激励及界面摩擦影响,采用集中质量法建立了某V20型柴油机配气凸轮轴系摩擦动力学分析模型,获取了配气凸轮轴系强迫振动结果,并分析了转速波动工况下配气凸轮副的摩擦润滑特性。结果表明,综合考虑各凸轮副瞬变激励及摩擦激励作用,配气凸轮轴系各轴段附加应力增大约4 MPa,且轴端瞬时转速波动量提高约±30 r/min;转速波动加之粗糙度作用,使得配气凸轮副膜厚明显减小,特别是在凸轮基圆段内,膜厚降低约0.3μm,接触润滑状态恶化;在凸轮副反向运动位置及桃尖处,挺柱界面温升超出材料胶合温度,易致胶合磨损失效问题。The camshaft is an important component that ensures the timely opening and closing of valve in marine diesel engines.Due to the poor contact lubrication state and excessive friction excitation,it is easy to cause larger interface torque on the camshaft.Considering the effects of transient excitation and interfacial friction,the tribo-dynamics model of the valve camshaft in V20 diesel engine is established.The forced vibration results of the camshaft are obtained,and the friction and lubrication performance of the cam-tappet pair is also analyzed under the fluctuating speed.The results show that,by thoroughly considering both the transient excitation and frictional excitation of each cam pair,the additional stress in each shaft section of the valve camshaft increases by about 4 MPa,while the transient speed fluctuation at the camshaft end increases by roughly±30 r/min.Under the combined effects of speed fluctuation and surface roughness,the film thickness is dramatically reduced in some positions,especially in the cam base circle section where the film thickness decreases by about 0.3μm.At the reverse motion position and nose of the cam,the temperature rise at the interface of the tappet exceeds the material’s scuffing temperature,thereby increasing the risk of scuffing wear.

关 键 词：配气凸轮轴 摩擦动力学 船用柴油机 扭转振动 附加应力 

分 类 号：TH132.47[机械工程—机械制造及自动化] O313.5[理学—一般力学与力学基础]