果园链索系统横向运动共振条件及频率分析(英文)  

Transversal vibration analysis of resonance condition and frequency for orchard chain ropeway system

作　　者：李君[1,2] 李雪平[1,2] 杨洲[1,2] 洪添胜[1,2] 薛坤鹏[1,2] 李伟[1,2] 

机构地区：[1]华南农业大学工程学院,广州510642 [2]华南农业大学南方农业机械与装备关键技术教育部重点实验室,广州510642

出　　处：《农业工程学报》2014年第23期50-57,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：Foundation item:The project of high level talents in Colleges in Guangdong Province(Guangdong finance education[2011]No.431);National Natural Science Foundation of China(Grant No.51205139)

摘　　要：为抑制果园链索货运系统的横向振动,需要预测振动频率特性的影响因素及其关联性。基于弦线理论和链传动特性,建立了拉普拉斯域内的横向振动微分方程,得到了系统运行的临界速度。对托索轮与链环之间的多边形效应进行了研究,确定了共振响应的行进速度条件。通过偏微分方程的数值求解,分析了链索初始张力、行进速度和载重质量对链索横向振动频率的影响关系,并进行了试验验证。试验条件下,行进速度、载重质量和张紧力的实际频率值与数值求解值的相对误差范围分别为1.4%~27.6%,6.1%~14.2%和14.7%~24.3%。结果表明系统一阶固有振动频率与张紧力正相关,与行进速度、载重质量负相关,所提出的模型能预测链索系统的运行参数对横向振动频率的影响。该研究为系统运行参数的优化提供了设计参考,并为链索货运系统受风雨激励影响和稳定性控制的研究提供了理论基础。To suppress the transverse vibration of an axially moving chain system with concentrated inertial masses in hilly orchard, the important factors affecting frequency characteristic of moving chain and their interaction are required to be studied. Based on the string theory and dynamics of chain transmission, the differential equation of transverse vibration was developed in the Laplace domain and the critical transport velocity was obtained in this paper. The stable condition for transport velocity corresponding to resonance was determined by considering the polygon effect causing speed variation when the moving chain link engaging with supporting end. With solutions for the second-order homogeneous partial differential equation, the effects of initial tension, transport velocity and load mass on the frequency of transverse vibration were numerically and experimentally analyzed. The difference between measured data and calculated data yielded values from 1.4% to 27.6% for various transport velocities, from 6.1% to 14.2% for various load masses, and from 14.7% to 24.3% for various initial tensions. The results show that the frequency of transverse vibration of axially moving chain increases with the increase in initial tension. The negative effect of transport velocity and load mass on vibration frequency in the case of forced nonlinear vibration is found. The proposed differential equation is proved valid to predict the effects of operation parameters on vibration frequency. It is conformed that this approach to transverse vibration of an axially moving chain can be used for parameter optimization under a certain constraint condition. The solution provides the theoretical basis for the vibration analysis and stability control of moving chain by consideration of wind-induced and rain-induced effects.

关 键 词：农业机械 运输 振动 行进链索 果园 横向振动 频率 

分 类 号：S229.1[农业科学—农业机械化工程] TD527[农业科学—农业工程]