混合动力挖掘机轴系扭振特性

Hybrid Excavator Shafting Torsional Vibration Characteristics

建立了混合动力挖掘机轴系的有限元分析模型,对轴系前5阶模态进行了计算。计算结果表明:与传统挖掘机相比,混合动力挖掘机轴系的1阶模态频率下降了270 Hz;前2阶模态的振型均为扭转振动。建立了混合动力挖掘机轴系的动力学仿真模型,对轴系的扭振特性进行了仿真研究。仿真结果表明:混合动力系统轴系存在周期性的扭振,扭角变化幅度为±0.003°,扭振频谱存在峰值,峰值频率约为48.9 Hz。建立了混合动力挖掘机轴系扭振测试实验台,对不同转速下轴系的最大扭角进行了实验测试。实验结果表明:当混合动力系统轴系转速大于1100 r/min时,轴系的最大扭角保持不变,约为0.003°;当混合动力系统轴系转速小于1100 r/min时,轴系的最大扭角随转速的减小而增大;当轴系转速为896 r/min时,轴系的最大扭角约为0.007°。

Hybrid excavator shafting finite element analysis model was established and shafting first 5 order modals were calculated. Modal calculation results show that hybrid excavator shafting 1 order modal frequency is decreased by 270 Hz compared with traditional excavator shafting. Modal shapes of first 2 order modal are torsional vibration. Hybrid excavator shafting dynamic simulation model was established to obtain shafting torsional vibration characteristics. Simulation results show that shafting torsional vibration is periodic. Torsional angle amplitude is about ±0. 003°. There is a peak in torsional angle frequeney spectrum. The peak frequency is about 48.9 Hz. Hybrid excavator shafting torsional vibration test table was established and torsional vibration testing with different ro- tate speeds were carried out. Experimental results show that shafting maximum torsional angle is about 0. 003° when shafting speed is greater than 1100 r/min. Shafting maximum torsional angle is de creased with rotate speed increasing when shafting speed is less than 1100 r/min. Shafting maximum torsional angle is about 0. 007° when shafting speed is 896 r/min.