CVT刚性联接发动机曲轴轴系结构的扭振分析

因非道路车辆的特殊结构和成本限制,提出四缸柴油发动机中采用CVT刚性联接曲轴轴系结构。阐述了该新型结构的特征和工作原理,建立了四缸柴油发动机离合式曲轴计算模型和CVT刚性联接曲轴计算模型。通过曲轴前端实验,证明了所建模型和模型参数确定方法的正确性。求解所有计算模型,并对结果进行对比分析。结果表明,CVT刚性联接使曲轴轴系振动波动加大,减振器耗散能增加,各阶共振峰值对应转速低减。对曲轴各拐剪切应力幅度的影响不大,但有高转速工况降低而中低转速剪切应力幅值增加的普遍趋势,CVT端的扭振振幅和剪切应力较大些。综合研究得出结论:非道路车辆低速四缸柴油发动机可以采纳CVT刚性联接曲轴轴系结构。

Torsional vibration analysis of the crankshaft with rigidly coupling CVT

Due to the limitation of non-road vehicles'' structure and cost, a structure of four-cylinder diesel engine crankshaft with rigidly coupling CVT was proposed. Characteristics and working principles of the new structure were presented. Calculation models were established separately for rotational vibration analysis of the newly proposed structure and the crankshaft with clutch. By carrying out the crankshaft front-end experiment, the presented model and the calculation method were validated. After solving both models for torsional vibration characteristics and parameters, results were compared. The comparison indicates that crankshaft with rigidly coupling CVT make the vibration fluctuation and the crankshaft dissipation power increase while the corresponding speed of resonance peak value decreases. The impacts on crank shear stress turn out to be small, while the shear stress tends to decrease at low speed condition and increase at high speed condition. Also, the torsional vibration amplitudes and shear stress at the end of CVT are larger. Through the comprehensive comparison, it can be concluded that the crankshaft with rigidly coupling CVT can be adopted on non-road low-speed four-cylinder diesel engine.