挖掘激励下斗轮机振动响应及影响因素研究

Vibration Response and Influence Factors of Bucket Wheel Excavators under Digging Excitation

斗轮机的振动是导致结构失效的关键原因。为此,通过拉格朗日方程建立斗轮机的4自由度离散动力学模型。基于动力学模型,研究4种典型工作姿态下斗轮机系统对挖掘阻力激励的响应,结果表明当斗轮机构处于最低位置时系统的位移和加速度响应最剧烈。针对此工况,进一步研究关键结构的刚度、以及斗轮质量对斗轮机系统固有频率以及振动响应的影响规律,结果表明:系统的前4阶固有频率对结构刚度的敏感性各不相同;斗轮质心振动位移随着斗轮质量和斗轮悬臂刚度的增加而单调减小;斗轮质心加速度大小随斗轮质量量增加而单调减小,而对悬臂拉杆刚度的变化不敏感。研究结果可为斗轮机上部结构的动力学设计提供理论依据。

Vibration of bucket wheel excavators is an important reason for structural failure.For this reason,a4-DOF discrete dynamic model of the bucket wheel excavator is established by Lagrangian equations.Based on the dynamic model,the response of the bucket wheel system to the excavation resistance under four typical working attitudes is studied.The results show that the displacement and acceleration responses of the system are the most severe when the bucket wheel is located at the lowest position.For this working condition,the influences of the key structure stiffness and the bucket wheel weight on the natural frequency and the vibration response of the bucket wheel system are studied.The results show that the sensitivities of the first4orders natural frequencies to the structural stiffness are different one another;the vibration displacement at the mass center of the bucket wheel reduces monotonically with the increase of the bucket wheel mass and the stiffness of the bucket wheel cantilever.The acceleration at the mass center of the bucket wheel monotonically decreases with the increase of the bucket wheel mass,but it is not sensitive to the change of the stiffness of the bucket wheel cantilever.The results may provide a theoretical basis for the dynamic design of bucket wheel structures.