秸秆还田机振动特性分析与试验研究

Analysis on vibration characteristics of the straw returning machine

针对秸秆还田机机壳与刀辊轴处受随机激振力产生振动问题,本研究以1JH-185秸秆还田机为研究对象,基于SolidWorks软件建立秸秆还田机的三维模型并进行优化设计与制造。应用ANSYS Workbench软件求解自由模态下机壳与刀辊轴前12阶的模态频率与振型。仿真结果表明:机壳模态频率范围处于42.68-205.97 Hz范围,刀辊轴模态频率处于356.39-1524.80 Hz范围,机壳固有频率远小于刀辊轴的模态频率。选择机壳中心与刀辊轴处作为非田间试验振动监测拾振点,利用DH187E加速度传感器和DHDAS动态信号测试分析系统测得秸秆还田机在高速运转工况下机壳中心与刀辊轴处各自的时域信号,经过傅里叶变换分析获得各自的频域信号,进而获得频域信号中的10个峰值点。非田间振动试验结果表明:模态分析频率与非田间振动频率结果基本吻合。机壳中心振幅为301.80 m/s^(2),峰值点6处最大频率为150.39 Hz,刀辊轴处振幅均值为295.28 m/s^(2),峰值点4处最大频率为150.39 Hz。可知对秸秆还田机振动影响较大的激励几乎都出现在机壳附近。研究结果表明,机壳模态频率与非田间振动频率均远小于刀辊轴模态频率与非田间振动频率,工作时振动更为敏感。本研究可为秸秆还田机避免共振危害、结构动力特性分析及保障机具寿命等研究提供参考。

There is vibration caused by random excitation force at the shell of the straw returning machine and the knife roller shaft.In the study,a 1JH-185 straw returning machine was selected to solve the problem.A three-dimensional model of the straw returning machine was established based on SolidWorks software,and the optimal design and manufacture was carried out.ANSYS Workbench software was used to solve the modal frequencies and mode shapes of the first 12 orders of the shell and the knife roller shaft in the free mode.The simulation results showed that the modal frequency of the shell ranged from 42.68 to 205.97 Hz,and the modal frequency of the knife roller shaft was in the range of 356.39-1524.80 Hz.The natural frequency of the shell was much smaller than the modal frequency of the knife roller shaft.The center of the shell and the knife roller shaft were selected as the vibration monitoring points for non-field experiments.The DH187E acceleration sensor and the DHDAS dynamic signal test and analysis system was adopted.The respective time domain signals of the shell and the knife roller shaft center were measured under the high-speed operation of the straw returning machine.After Fourier transform analysis,the respective frequency domain signals and 10 peak points in the frequency domain signals were obtained.The modal analysis frequency was basically consistent with the non-field vibration frequency results.The amplitude of the center of the shell was 301.80 m/s^(2).The maximum frequency at the peak point 6 was 150.39 Hz.The average amplitude of the knife roller shaft was 295.28 m/s^(2).And the maximum frequency at the peak point 4 was 150.39 Hz.Therefore,the excitations with great impact on the vibration of the straw returning machine were mostly near the shell.The research results showed that the modal frequency and non-field vibration frequency of the shell were much smaller than that of the knife roller shaft,and the vibration was more sensitive during operation.The research provides a reference for the research on avoiding resonance hazards,analyzing the structural dynamic characteristics and ensuring the life of the straw returning machine.