偏摆式天然橡胶割胶装置转子振动特性分析与结构优化设计  

Vibration characteristics analysis and structural optimization design of rotor in natural rubber cutting device with pendulum

作　　者：邓祥丰 陈娃容 吴思浩 粟鑫 范博 肖苏伟 Deng Xiangfeng;Chen Warong;Wu Sihao;Su Xin;Fan Bo;Xiao Suwei(Rubber Research Institute,Chinese Academy of Tropical Agricultural Sciences,Haikou,571101,China;Mechanical Sub-center of National Important Tropical Crops Engineering Technology Research Center,Haikou,571101,China)

机构地区：[1]中国热带农业科学院橡胶研究所,海口市571101 [2]国家重要热带作物工程技术研究中心机械分中心,海口市571101

出　　处：《中国农机化学报》2025年第3期25-32,共8页Journal of Chinese Agricultural Mechanization

基　　金：海南省自然科学基金项目资助(521QN0937,323MS074);海南省科技专项资助(ZDYF2021GXJS009)。

摘　　要：偏摆式天然橡胶割胶装置的激振动力是由转子在高转速下形成的冲击载荷所产生,从而造成切割刀头内部出现受迫振动,引起构件间发生疲劳磨损。通过理论计算构建偏心转子的运动方程与模型参数,利用CAE软件对传动结构模型进行仿真模拟,分析驱动叉与刀座连接处出现磨损的原因,构建传动结构FEM模型,对比优化前后的传动结构应力分布、疲劳寿命强度等状态特征。试验表明,当转子自有转速大于7000 r/min时,运动轨迹开始失稳不再重合,转子—驱动叉间的冲击载荷也随转速提升而增大,导致驱动叉与刀座连接处容易出现应力集中;通过改变驱动叉内壁与偏心转子的接触结构,可有效应对冲击载荷对传动结构的影响,通过数值分析,传动结构整体的最大应力可降低25.8%。结果表明,转子—驱动叉的接触方式由平面接触改为曲面接触后,能够有效降低传动结构的应力产生及保障结构的疲劳寿命强度,同时,适当降低偏心转子的转速,可减缓冲击载荷对传动结构的影响。The excitation force of the natural rubber cutting device is generated by the impact load formed by the high-speed rotation of the rotor,resulting in forced vibrations inside the cutting head and fatigue wear among the components.A motion equation and model parameters for the eccentric rotor are developed through theoretical calculations,and the transmission structure model is simulated by CAE software.The causes of wear at the connection between the drive fork and the cutter seat are analyzed,and the FEM model of the transmission structure is constructed to compare the stress distribution,fatigue life strength and other characteristics of the transmission structure before and after optimization.The test shows that when the rotor speed exceeds 7000 r/min,its motion trajectory becomes unstable and no longer coincides,and the impact load between the rotor and the drive fork increases with the increase of the speed,which leads to the stress concentration at the connection between the drive fork and the tool holder.By modifying the contact structure between the inner wall of the drive fork and the eccentric rotor,the impact of the impact load on the drive structure can be effectively dealt with.Through numerical analysis,the maximum stress of the whole structure can be reduced by 25.8%.The results show that the changing from planar contact to curved contact can effectively reduce the stress generation in the transmission structure and ensure its fatigue life strength.Also,appropriately reducing the rotor speed can mitigate the adverse effects of impact loads.

关 键 词：偏心转子 天然橡胶 切割刀头 振动 运动轨迹 

分 类 号：TH122[机械工程—机械设计及理论]